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TM ^1709 



MHI 




-t<w 


^ 1 

WAR DEPARTMENT 




TECHNICAL MANUAL 




ORDNANCE MAINTENANCE 




CHASSIS AND BODY FOR 




SCOUT CARS M3A1 




September 22, 1942 



m 



mm 

AVAILABLE 



TM 9-1709 



TECHNICAL MANUAL, 1 WAR DEPARTMENT, 

No. 9-1709 J Washington, September 22, 1942. 

ORDNANCE MAINTENANCE 

CHASSIS AND BODY FOR SCOUT CARS M3A1 

Paragraphs 

Section I. General , 1 

II. Service maintenance 2-3 

III. Technical inspection 4-6 

IV. Body and sheet metal , 7-9 

V. Brake systems 10-18 

VI. Cooling system 19-22 

VII. Electrical lighting system ; battery and accessories 23-29 

VIII. Frame 30-33 

IX. Fuel system 34^38 

X. Instruments and gages 39-42 

XL Springs and shock absorbers 43-45 

XII. Steering gear and drag link 46-52 

XIII. Consolidated service data (fits and clearances) 53-59 

XIV. Care of units in extreme temperatures or under 

unusual conditions 60-62 

Page 

Appendix. List of references 257 

Index 259 

Section I 
GENERAL 

Paragraph 
Scope : 1 

1. Scope. — This manual is published for the information and 
guidance of ordnance maintenance personnel, and is one of a series of 
five maintenance publications on scout cars. It contains detailed in- 
structions for inspection, disassembly, assembly, maintenance, and re- 
pair of the scout car M3A1 supplementary to those in the Field and 
Technical Manuals prepared for the using arm. Additional descriptive 
matter and illustrations are included to aid in providing a complete 
working knowledge of the materiel. 

a. The vehicle. — Information concerning lubrication of the entire 
vehicle will be found in TM 9-705 and TM 9-1705. 

477229°— 42 1 1 



TM 9-1709 

1-3 ORDNANCE MAINTENANCE 

b. Chassis and body. — Information is included in this manual con- 
cerning the detailed description, operation, inspection, and trouble 
diagnosis, disassembly, maintenance and repair, assembly, and test of 
major components of the chassis (exclusive of power train and power 
plant) and body, supplementary to that in TM 9-1705. 

c. Power train. — Maintenance information concerning the power 
train will be found in TM 9-1705. 

d. Power plant. — ^Maintenance information concerning the power 
plant and its accessories will be found in TM 9-1706, TM 9-1707, and 
TM 9-1708. 

Section II 
SERVICE MAINTENANCE 

Paragraph 

General 2 

Allocation of repair jobs 3 

2. General. — The primary objective of organization maintenance 
personnel is the routine preventive care and adjustment necessary to 
maintain efficient operation of vehicles. The primary objective of 
ordnance maintenance personnel is the technical inspection and repairs 
beyond the authorized capacity of the using arm. The scope of main- 
tenance repair operations is governed by weather, concealment, shelter, 
available equipment, tools and parts, and skill of personnel. Since 
these factors are variable, no rigid system of procedure can be 
prescribed. 

3. Allocation of repair jobs. — The following oi^erations augment 
those which may be performed by the using arm : 

a. Body. — Replace. 

(1) Body plates and supports. — Repair, replace, or I'ebuild. 

(2) Seats. — Repair or rebuild. 

(3) Sheet metal. — Repair, weld, or rebuild. 

(4) Tops. — ^Repair, weld, or rebuild. 

(5) Upholstering. — ^Repair or replace. 

(6) Windshield. — Repair. 

(7) Windshield wipers. — Repair or rebuild. 

b. Brakes. — (1) Brake cylinders. — Re])air and hone. 

(2) Braheshoes. — Reline. 

(3) Brake vaewu/m, 'booster. — Adjust, repair, and i-ebuild. 

c. Cooling system,. — (1) Fan. — Repair. 

(2) Fan &ea««^s.— Replace. 

(3) Radiator.- — ^Repair. 

(4) Water js^wnjs .-^Repair or rebuild. 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 3-6 

d. Electric lighting system, and accessories. — (1) Battery. — Repair. 

(2) Heater. — Eepair. 

(3) Horn. — Eepair. 

(4) Lights. — Repair. 

e. Frame. — (1) Frame. — Eepair or straighten. 

(2) Pintle. — Repair 

(3) Roller. — Replace or repair. 

/. Fuel system,. — (1) Fitel gage coinpoivents. — Eepair. 

(2) Fuel tanks. — Repair. 

(3) Carbwetor. — Repair or rebuild. 

(4) Fuel pum/p. — Repair or rebuild. 
g. Instruments. — (1) Chaster. — Repair. 
(2) Meters. — Repair. 

h. Sprimxjs and shock absorbers. — (1) Absorber's. — Repair. 

(2) Sfrimgs. — Eepair or rebuild. 

i. Steering gear. — (1) Drag link. — Eepair. 

(2) Steering gear. — Repair or rebuild. 

ij. Wheels. — (1) Line casings and tube. — Repair. 

(2) Wheels, — Repair, weld, machine, and aline. 

Section III 
TECHNICAL INSPECTION 

Paragraph 

Description 4 

Inspection form 5 

Practical application 6 

4. Description. — Technical inspections are a follow-up and check 
on organizational maintenance inspections and other maintenance 
functions and determine whether the vehicle should be continued in 
service or withdrawn from operation for overhaul. These inspections 
are covered in AR 850-15. 

5. Inspection form.— W. D., Q. M. C. Form No. 260 (Technical 
Inspection Report of Motor Vehicles), is the standard and official form 
for recording the inspection of all motor vehicles. The extent to 
which use is made of this form or its modifications depends entirely 
on the technical ability of available personnel, the time factor, and 
the test and shop' equipment available. 

6. Practical application. — a. External inspection of body and 
frame compoTients. — (1) Bumpers. — Examine for straightness ; use 
wrench to test channel bolts for tightness ; inspect brackets for breaks. 

(2) Toio hooks. — Inspect for straightness and fractures; use wrench 
to test mounting bolts for tiglitness. 

3 



TM 9-1709 

6 ORDNANOE MAINTENANCE 

(3) Front roller. — Check freedom of rotation; iiispect springs and 
supporting brackets for breaks. 

(4) Badiaior shutters. — Inspect for breaks in armor plate and loose 
screws ; open right door and operate louver lever to check opening and 
closing of shutters. 

(5) Radiator. — Examine underneath for leaks ; inspect front of core 
for plugged air passages. 

(6) Headlight guards. — Shake to determine looseness; inspect for 
breaks and fractures. 

(7) Tires. — Inspect for serviceability; examine for indications of 
improper inflation or use, cuts, blisters, breaks, uneven wear, etc.; 
record defects for each tire. 

(8) Toe-m.— Check (see sec. V, TM 9-1705). 

(9) Caster and cornier. — Check (see sec. V, TM 9-1705). 

(10) Hood. — Inspect for breaks in armor plate and loose screws; 
examine fasteners and hinges; inspect lacings for breaks; open and 
shut to check for fit. 

(11) Running hoards and fenders. — Examine for cracks and dents; 
shake up and down to test for looseness ; use wrench to test mounting 
bolts for tightness ; inspect support brackets for breaks. 

(12) Doors. — Open and close to test for fit; shake up and down 
while open to test for loose hinges; turn handles and check locks and 
latches; inspect for loose and missing screws; check operation and 
securement of obsei'vation slot covers. 

( 13) Glass. — Inspect windshields for cracks and fit ; check mounting 
detail ; examine for leaks and defective seals. 

(14) Body. — Inspect for breaks in armor plate and loose screws; 
examine under side for bent or broken frame, angles, battens, and 
welds; check for loosened floor plates; check securement of grab 
handles. 

(15) Paint. — Inspect for chipped paint, rust spots, scratches, bright 
metal, gloss, peelings, and cracks. 

(16) Top amd curtains. — Inspect for breaks in material and indi- 
cations of leaks ; examine straps and keepers. 

(17) Pintle. — Inspect towing device for securement; examine latch 
effectiveness ; check operation ; use wrench to test tightness of pintle 
hook retaining nut. 

(18) Lights. — ^Inspect for broken glass and reflectors; check wire 
connections ; use wrench to test tightness of headlamp mounting stud 
nuts; check securement of taillamps, turn on lights and check all 
bulbs for different positions of light switch ; be sure to turn off lights. 

(19) Arwrrmmition rachs. — Check covers; inspect shelves. 



TM 9-1709 

CHASSIS AJS'D BODY FOR SCOUT CARS M3A1 6 

(20) Battery and convpartment. — Remove top housing plate; check 
level and specific gravity of electrolyte in each cell ; check voltage drop 
across cells with tong tester ; examine terminals for looseness and corro- 
sion ; inspect cables and ground straps ; check vents and tighten plugs. 

i. External inspection of chassis components. — (1) Front axle. — 
Inspect for straightness ; shake wheels to check for "wobble" ; inspect 
cross tube; check for oil leaks and cracked housings; test all nuts 
with wrench; inspect brush guards and universal joint dust shields; 
check presence of necessary plugs and lubrication fittings and evidence 
of propel' lubrication ; inspect breather. 

(2) Wheels. — Check all wheel nuts with wrench; check lubrica- 
tion of bearings. 

(3) Springs. — Inspect for broken leaves, loose clips, worn or dam- 
aged shackles, and misaJinement; check shackle lubrication; test all 
shackle bolts with wrench; use pry bar to check flexing of springs. 

(4) Shock absorbers. — Check fluid level; examine linkage; inspect 
securement and lubrication. 

(5) Frame. — Inspect frame side rails and cross members for dis- 
tortion and fractures; examine front end for evidence of stress due 
to overhang of loads; inspect all rivets and especially those for the 
roller brackets, spring brackets, engine supports, and steering gear 
bracket ; examine battery tray support rivets for corrosion. 

(6) Steering gear housing. — Test all nuts with wrench ; while some- 
one turns steering wheel, observe housing for leaks, shimmy or loose- 
ness ; check lubrication. 

(7) Steering gear linkage. — Inspect drag link for straightness; 
check lubrication and presence of boots ; test all nuts with wrench. 

(8) Transfer case. — Inspect for leaks and cracked case; test all 
bolts with wrench; check presence of necessary plugs, lubrication 
of fittings and evidence of proper lubrication; inspect breather. 

(9) Transmission. — Inspect for leaks and cracked case; test all bolts 
M'ith wrench; check presence of necessary plugs and lubrication of 
fittings and evidence of proper lubrication ; inspect breather. 

(10) Propeller shafts. — Inspect for distortion and fractures; exam- 
ine flanges; test all nuts with wrench; tighten dust caps; check 
lubrication and relief valves. 

(11) Brake linkage. — Check all clevis pins for lubrication, presence 
of cotter pins, and looseness; inspect rods for straightness, cracks, rust, 
and corrosion. 

(12) Brake lines. — Check for leaks, breaks, and loose connections; 
examine flexible tubing for cracks. 

(13) Vacuum, booster. — Examine linkage and securement. 



TM 9-1709 

6 ORDNAKCE MAESI'l'EKAN'CE 

(14) Fuel lines. — Check for leaks, breaks, and loose connections. 

(16) Rear axle. — Check for oil leaks and cracked housing ; test all 
nuts with wrench; check presence of necessary plugs and lubrication 
fittings and evidence of proper lubrication ; inspect breather. 

(16) MiMffler and tail pipe. — Check for breaks, dents, and corrosion; 
examine and tighten supporting details; inspect for any obstacles in 
exhaust pipe. 

c. Engine compartment {engine stopped). — (1) Radiator. — Exam- 
ine for leaks, rust, corrosion, and clear air passages; shake to observe 
if it is loose in the frame; tighten all stud nuts with wrench; check 
clearance of fan blades; check vent; check for presence of radiatoi' 
cap and proper water level; test antifreeze solution with suitable 
hydrometer. 

(2) Fan. — Inspect blades for breaks, looseness, and proper pitch; 
shake to test for looseness and worn bearings. 

(3) Fan T)elt. — Inspect for matching of belts and play ; examine for 
fraying, tears, and presence of grease or oil; check alinement of 
pulleys. 

(4) /i^AroM^?.— ^Inspect for fit and securement; check cleai-ance of 
fan blades; tighten screws. 

(5) Water pump. — Check for end play of pulleys and alinement; 
inspect housing for cracks and leaks; examine' securement of hous- 
ing to engine. 

(6) Oil -filter. — Check for securement; examine cartridge. 

(7) Engine lubrication,. — Check oil level. 

(8) Fuel filter. — Inspect for leaks; examine securement; examine 
bowl for sediment and water ; check filter element. 

(9) Carbwretcw. — Inspect for leaks; examine securement; check 
control linkage. 

(10) Air cleaner. — Examine cleaning element and bowl for ex- 
cessive dirt; check oil level; inspect hose to carburetor and connector 
to engine ; examine securement. 

(11) Fuel pwmp. — Inspect for fuel and oil leaks; examine secure- 
ment; examine bowl for sediment; check screen. 

(12) Distributor. — Examine cap for cracks, condensation, and dirt; 
inspect motor; separate and examine points for pits and burns; in- 
spect cams ; check shaft for "wobble" ; examine insertion and connec- 
tion of wires in cap. 

(13) Shielding. — Examine conduit for breaks and securement; dis- 
connect from spark plugs; examine and tighten latter; inspect in- 
terior of caps for condensation; check cable and terminals; tighten 
clamp nuts. 

6 



TM 9-1709 

CHASSIS AOSTD BODY FOR SCOUT CARS M3A1 6 

d. Interior inspection {engine started). — (1) Switches. — Check 
operation; examine securement; inspect wiring. 

(2) Meters. — Check operation; examine securement; inspect con- 
nections. 

(3) Gages. — Check operation; examine securement; inspect con- 
nections; feel tachometer and speedometer cables for excessive heat 
and vibration. 

(4) Windshield wipers. — Check operation. 

(5) Panel lights. — Check operation. 

(6) Horn. — Check operation. 

(7) Fire extinguisher. — Check securement; inspect for full charge. 

(8) Choke and ventilator controls. — Check free operation and note 
movement of ventilator slides; have an assistant note movement of 
choke valve in carburetor. 

(9) Accelerator. — Check for proper alinement and operation. 

(10) Pedals. — Check for proper operation. 

(11) Brake fluid. — Remove floor cover in front of driver's seat 
and inspect master cylinder; examine fluid; check securement and 
connections. 

(12) Louver control lever. — Operate lever to check movement and 
position of radiator shutters. 

(13) Seats. — Inspect for breaks, damaged brackets, and upholstery. 

(14) Gwn rail pads. — Inspect. 

(15) Gun rail. — Inspect for breaks, cracks, and rust; examine se- 
curement around entire circumference and operate gun carriage 
around each corner to check alinement. 

(16) Top bows. — Inspect bows for breaks and securement. 

e. Engine compartment {engine running). — (1) Engine noises. — 
Accelerate engine sharply and listen for knocks and unusual noises; 
listen for valve chatter. 

(2) Engine smoothness. — Accelerate engine slowly to different 
s]3eeds and check smoothness of running. 

(3) Engine mounting. — Inspect front and rear supports for se- 
curement. 

(4) Gaskets. — Inspect all cover, housing, and accessory mounting 
gaskets for oil and water leaks. 

(5) Fuel leaks. — Inspect carburetor, fuel pump, and fuel lines for 
leaks. 

(6) Oil leaks. — Inspect under vehicle and bottom of oil pan for 
evidence of oil drippings. 



TM 9-1709 

6 OEDNANCE MAINTENANCE 

(7) 'Water leaks. — ^Inspect hose connections to radiator, water 
pump, and heater for leaks; feel hose for condition of fabric and 
flow of fluid; examine radiator for leaks. 

(8) 'Wiring. — Inspect "wires around engine and along frame; tug 
on wires to check for loose connections evidenced by sparking; ex- 
amine terminal board connections. 

(9) Voltage regulator. — Disconnect lead to battery and use volt- 
meter to check for correct cut-out and open-circuit voltages. 

/. Road test. — (1) Body noises. — ^Listen for any unusual body 
noises, squeaks, or rattles, and identify location and cause. 

(2) Drive shaft hrahe. — Test by pulling on hand brake lever and 
gently engaging clutch to stall the engine; note any unusual noises 
or signs of loose parts; do not attempt to stop rolling vehicle with 
this brake. 

(3) Service hraJces. — ^Test by applying pressure to foot pedal and 
observing results, including tendency of vehicle to swerve or stall. 

(4) Clutch. — Check for smoothness of operation. Test for effec- 
tiveness by setting drive shaft brake, or using the service brakes, putting 
the vehicle in low gear, and releasing the clutch pedal gradually; if 
the clutch is efficient, the engine should stall. 

(5) Gea/r hox. — ^Listen to transmission and transfer case gears for 
a high pitched whine or squeal which indicates internal misalinement 
or improper adjustment. In shifting gears, it is usual for the two 
lower speeds to be much noisier in operation, than high gear ; unusual 
noises in the transmission where operating in the high gears should be 
investigated immediately to avoid severe damages. 

(6) Gear shift. — Check to see that the gear shift levers are firmly 
fastened in their retaining sockets and that the gear shift forks on 
the lower end of the levers move properly through all gear changes 
selected. 

(7) Speedometer amd toGhometer cables. — Observe instruments to 
note registering. Feel cable; if hot, internal friction is developing 
due to improper adjustment or lack of lubricant; if a slight click or 
thump is heard, remove the cable and inspect for distortion, incorrect 
length or diameter, or breaks. 

(8) Steering mechanism. — Note if steering wheel has a tendency to 
jerk; such action indicates a looseness in the steering mechanism con- 
nection from the front axle to the wheel, or an error in steering geom- 
etry. Note any tendency on the part of the vehicle to wander or drive 
to the right or left, indicating improper adjustment, or an error in 
steering gear geometry. If a thump or knocking is felt in the steering 
wheel, a part is probably loose in the steering gear worm. 



TM 9-1709 

CHASSIS AN-D BODY FOR SCOUT CARS M3A1 6-7 

(9) Engine noise. — Light clicking or tapping noises usually indicate 
incorrect adjustment of valves ; heavy thumping noises usually indicate 
engine bearing trouble; squeals and squeaks usually indicate loose 
fastenings or lack of lubrication in the generator, water pump, distribu- 
tor, and similar accessories operating at high speed. 

(10) Engine smoothness. — A balky engine can be detected by an 
experienced driver and is usually indicated by jerky motions of the 
vehicle or other signs that point to a misfiring cylinder. Have an 
assistant note exhaust gases. 

(11) Engine potcer. — An engine not developing its power can be 
detected by driving the vehicle up a hill or under load, or by noting 
a frequent need to shift from the high range of speed gears to the lower 
range. 

Section IV 

BODY AND SHEET METAL 

Paragraph 
Body 7 

Sheet metal 8 

Windshield wipers 9 

7. Body (figs. 1 to 12, inch). — The vehicle body is made of i^ inch 
thick armor plate, with the exception of the windshield plate and 
windshield porthole covers, which are ^ inch thick. The plates are 
bolted to the body framework with oval-head screws and safety (elastic 
stop) nuts. The entire body assembly is bolted to the chassis frame 
assembly. The floor plates are made of checkered aluminum and are 
bolted to the body framework. 

a. Disassembly. — (1) The side doors, door shields, windshield plate, 
and side and top hood plates are all hinged and are dismounted by 
removing the oval-head screws or bolts and self-locking nuts with 
which the hinges are bolted to these units. To detach the porthole 
covers on the windshield plate and side doors, remove the oval-head 
bolts and self-locking nuts holding the brackets. For the covers of 
the ammunition racks, undo similar bolts and nuts holding the angle 
bars by which the hinges are secured to the sides of the body. An air 
wrench is usually necessary to remove the self -locking nuts. 

(2) The remaining body plates and the floor plates are released by 
removing the screws and nuts holding them in place. 

&. Maintenance. — (1) Keplace all damaged bolts and screws as soon 
as practical. 

(2) Remove bent armor plates and straighten by cold bending. Do 
not attempt to use heat for straightening, since this will change the 
hardness of the plates and their ability to resist penetration by gunfire. 

9 



TM 9- 

7 



1709 



ORDNANCE MATXITSNANCE 



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TM 9-1709 

FOR SOOUT OARS M3A1 7 



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11 



TM 9-1709 

7 



ORDNANCE MAINTENANCE 



WVUT SRQPN MLKJ HGFEDC 




A. Bumperette (left-hand) WI-347321. 

B. Marker lamp GL-916388. 

C. Headlamp Gr.-917743. 

^ „ /(right-hand) WI-C2418X. 

° {(left-hand) ■WI-C2419X. 
E. Armor plate DS-PA-3042 (No. 55). 
F Support /<'"*Sht-hand) DS-H-13167AR. 

'^'^ \ (left-hand) DS-H^13167AL. 
G. Frame DS-H-11736AL. 
H. Frame DS-H-11736B. 
J. Armor plate DS-PA-3042 (No. 53). 
K. Wiper TEI-618A. 
L. Armor plate DS-PA-2752 (No. 13). 
M. Support DS-H-13167E. 



T. Rod assembly J 



N. Rod assembly DS-H-13181E. 

P. Leaf DS-H-13064. 

Q. Support DS-H-13167D. 

E. Support DS-H-13167. 

S. Louver assembly DS-PA-3055. 

f (right-hand) DS-H-13181E. 
''l(left-hand) DS-H-13181L. 
U. Armor plate DS^PA-3043 (No. 64). 
V. Bracket BA-B147. 
W. Guard assembly WI-347352. 
X. Frame DS-H-11736AR. 
Y. Bumperette (right-hand) WI-347322. 
Z. Spring WI-347345. 
AA. Roller assembly WI-347312. 



FiGtisB 3. — Scout car M3A1, body — front view. 



12 



TM 9-1709 

CHASSIS AND BODY FOK SOOTJT OARS M3A1 7 




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A. Handle DS-H-13161. 

B. Strap assembly A165660. 

C. Armor plate DS-PA-3083 (No. C8). 

D. Strap assembly B158641. 

E. Strap assembly A156672. 

F. Tail lamp CB-647135. 

G. Support DS-H-13129E. 
H. Bracket assembly C69112. 

J. Bumper assembly DS-PA-3702. 



•jlA PD I8S5B 



I k 1 

K. Clamp assembly C69075. 

L. Support DS-H-13128. 

M. Armor plate DS-PA-3083 (No. 69) 

N. Bracket C69111. 

P. Support DS-H-13129L. 

Q. Clamp A171945. 

E. Strap A165663. 

S. Strap A165666. 

T. Loop BB-6400C. 



FiGUEE 4. — Scout car M3A1, body — rear view. 



13 



TM 9-1709 

7 



ORDNANCE MAINTENANCE 



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A. Plate DS-H-1S070. M. 

B. Rack, ammii-l steel, DS-H-13184R. X. 

nitlon. /aluminum, DS-H-13191R. P. 

C. Seat DS-PA-3070. Q. 

D. Plate DS-H-13169B. K. 

E. Seat DS-PA-3082. 

r Rack, ammu- r steel, DS-H-13183. S. 
F.l nitlon. "[aluminum, DS-H-13192. T. 

[Plate DS-H-13130. U. 

G. Plate DS-H-13120. V. 

H. Plate DS-H-13123. W. 

J. Plate DS-H-13101. X. 

K. Plate DS-H-13135A. Y. 

L. Plate DS-H-13828. Z. 



Y Z 

Plate DS-H-13825A. 

Plate DS-H-13100L. 

Bulkhead assembly DS-H-13164. 

Mast assembly DS-H-13169. 

Rack, ammu- [steel, DS-H-13184L. 

nitlon. jaluminum, DS-H-13191L. 
Plate DS-H-13070. 
Track assembly DS-H-13824. 
Gusset DS-H-13137. 
Plate DS-H-13075L. 
Plate DS-H-13073L. 
Plate DS-H-13072. 
Plate DS-H-13073E. 
Plate DS-H-13075R. 



PiGUBB 5. — Scout car M3A1, body — -plan view. 



14 



TM 9-1709 

CHASSIS AJSTD BODY FOR SCOUT CARS M3A1 7 




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TM 9-1709 

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16 



TM 9-1709 

CHASSIS AND BODY FOiR SCOUT OARS M3A1 7 



BRACKET, ASS'Y.-DS-H-ll8lfR 
ARMORPLATE-DS-PA-3053 ( 3) 
ARMORPLATE-DS-PA-2753 { 2) 
ARMORPLATE-DS-PA-3046 ( 4) 
PLATE-DS-H-I3I65 



SCREW, THUMB-EB-545IB 



BRACKET, ASS'Y.-DS-H-I18IIL- 
LEAF,HIN6E-DS-H-I3064 




STUD-DS-H-13180 — 

CLAMP, ASS'Y.-DS-H-I3I82 
NUT, WING -BBPXID 
R0D,ASS'Y.-DS-H-I3I8IL 




NOTE 



SCREWS THRU ARMORPLATE EXCEPT AS NOTED, ARE 
NICKEL-STEEL,OVAL-HEAD, MACHINE SCREWS, 
^r"-24NF-2 (AMERICAN STANDARD), WITH SAFETY 



NUTS,?'g-24NF-3 



'® 



RA FSD I857B 



Figure 8. — Windshield armor details. 



477229°— 42- 



17 



TM 9-1709 
7 



ORDNANCE MAINTENANCE 




18 



TM 9-1709 

CHASSIS AKD BODY POE SOOUT CARS M3A1 7 







19 



TM 9-1709 

7 



ORDNANCE MAINTENANCE 




TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 7 



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21 



TM 9-1709 

7 



ORDNAIfCE MAJNTENANCB 




A. Control WI-334908. 

(■Control WI-334907. 
bJ Nut BBBXIC. 

[washer, lock, BBCXIK. 

C. Control WI-348751. 

D. Grommet WI-A17298X. 

{Support WI-316216. 
Screw, cap, BCBXICB. 
Nut BBBXIC. 
Washer, lock, BBCXIK. 
F. Bracket WI-316215. 

r Screw, cap, BCBXICB. 
a.} Nut BBBXIC. 

[washer, lock, BBCXIK. 



RA PD 32S1A 

H. Box, shielding, assembly WI-368514. 
J. Grommet WI-A10766X. 
K. Grommet WI-348796. 
L. Grommet WI-10347X. 
.\I. Grommet WI-17298X. 

{Shaft SW-95000-84. 
Clip WI-27593X. 
Screw, cap, BCBXIAA. 
Nut BBBXIA. 
Washer, lock, BBCXIG. 
P. Grommet WI-A13934X. 
Q. Grommet WI-A17218X. 



FiGtjRB 12. — Dash and instrument shielding box. 



22 



TM 9-1709 

CHASSIS AND BODY FOE SCOUT CARS M3A1 7-8 

(3) Plates which are pierced by shells should be replaced with new 
ones. If necessary, temporary repairs can be made by bolting a sec- 
tion of plate over the shell hole. Armor plate can be repaired by 
welding according to instructions specified in TB 1852-1. 

(4) Replace damaged springs on the radiator louver control lever 
ratchet rod and port hole bracket plunger; replace damaged hinges 
and any other worn or damaged parts. 

8. Sheet metal. — a. Fenders. — (1) Description. — The front wheel 
fenders are made of pressed steel. The outside edges are turned over 
to form a bead for reinforcing jjurposes to prevent breaking or teai'ing. 
Each fender has two supports which are welded to the fender at 
their outer edges. The front support is bolted to the frame and the 
rear support is bolted to the engine side armor plate. The fenders 
are also bolted to the engine side plates and running boards. The 
headlamps and guards are bolted to the top of the fenders at the 
front. The headlamp cables are disconnected by turning and removing 
the terminal plugs at the rear of the lamps; and the blackout marker 
lamp wires are detached from the connectors under the fenders and 
pulled through grommets in the fenders below these lamps. 
(2) Disassembly. — Tools: 

3/2-inch socket wrench. %-inch open-end wrench. 

%-inch socket wrench. %6-inch open-end wrench. 

%6-roch socket wrencli. %6-inch open-end wrench. 

%g-inch socket wrench. 
{a) Eemove headlamp brush i^'ii'^ch socket wrench, 

guard and marker lamp. i^-inch open-end wrench. 

Disconnect blackout marker lamp No. 14 cable from connector 
WI-331080 underneath fender. Remove four bolts BCBXIBB, nuts 
BBBXIB and lock washers BECXIH holding each guard assembly 
WI-347352 to fender. 

(&) Remove headlamp. %-inch socket wrench. 

Disconnect headlamp wire at rear of lamp. Eemove nut BBBXID, 
lock washer BECXlL, and bearing washer WI-K12206 holding 
lamp to fender, and take off adapter A176422 and headlamp 
WI-368513. 

(c) Remove fenders. 

% 6-inch socket wrench. %6-inch open-end wrench. 

i/2-inch socket wrench. i/^-inch open-end wrench. 

%6-iiich socket wrench. ^g-inch open-end wrench. 



23 



TM 9-1709 

8 ORDNAN^CB MAESITENIANCB 

Kemove two nuts BBBXIC, lock washers BECXlK, screws 
BCBXICB, and spacers WI-354112 or WI-354113 holding each 
fender iron (front and rear) in place; nine nuts BBBXlA, lock 
washers BECXIG and screws BCBXIAA holding fender to armor 
plate; and three nuts BBBXlA, lock washers BECXIG and screws 
BCBXIAA holding rear of fender to running board support, and 
lift off fender assembly WI-347335 (left-hand), WI-347336 (right- 
hand). 

(3) Maintenance. — No maintenance is required on the fenders 
unless they are damaged in an accident or by shell fire. 

(a) Bent or crushed fenders can be repaired by pulling and ham- 
mering into shape. (See sec. IV, TM 10-450 for more detailed 
information.) 

(&) Torn or pierced fenders can be straightened by hammering and 
then welded. 

(4) Reassembly. — Tools: 

%6-™ch socket wrench. %6-iiich open-end wrench, 

i^-inch socket wrench. i/2-ir'ch open-end wrench. 

%e-inch socket wrench. %e-inch open-end wrench. 

%-inch socket wrench. 
{a) Replace fender. yiQ-iwch. socket wrench. 

i/^-inch socket wrench. 
%6-inch socket wrench, 
y^e-inch open-end wrench, 
i/^-inch open-end wrench. 
%6"iiich open-end wrench. 
Set fender in position and replace bolts, lock washers, and nuts 
holding fenders to frame, armorplate and running board support. 
(&) Replace headlamps. %-inch socket wrench. 

Set adapter and lamp assembly upon fender and replace bearing 
washer, lock washer and holding nut. Reconnect wire at rear of 
lamp. 

(c) Replace headlamp brush guards. %-inch socket wrench. 

%-inch open-end wrench. 
Attach headlamp brush guard to fender with bolts, lock washers 
and nuts. Reconnect blackout marker lamp wire under fender. 

h. Instrument panel. — The instrument panel requires no mainte- 
nance unless it is damaged in combat. When this occurs, the panel 
WI-368533 can be removed as an assembly in the following manner : 
Disconnect instrument wires and tubing, controls, instruments, 
switches, windshield wiper bosses, steering tube bracket, and instru- 



24 



TM 9-1709 

CHASSIS AM) BODY FOB SCOXJT CARS M3A1 8-9 

ment shielding box. Remove holding bolts, nuts, and lock washers and 
pull out assembly. Mark wires and controls to facilitate reassembly. 

G. Tool boxes. — ^In order to avoid accumulation of water in the 
tool box, drill a 14-iiich hole near the bottom of the tool box and 
countersink to remove the burs. Then thoroughly clean the inside 
of the tool box and paint all exposed metal surfaces. After the paint 
is dry, apply a film of engine oil to the inside surface of the tool box. 

d. Preservation of tools. — Inspect the tools supplied with the vehicle 
for rust. Thoroughly clean tools to remove rust on the working sur- 
faces and protect the surfaces by coating them with a thin film of 
engine oil. 

9. Windshield wipers (fig. 13). — a. Description. — The wind- 
shield wipers are of the vacuum type and are mounted on the left- and 
right-hand side of the windshield frame over the instrument panel. 

(1) Construction. — The body and cover of the wiper are aluminum 
die castings. The cover contains the vacuum and atmospheric pressure 
inlet, the exhaust ports and channels, and also the vacuum tube fitting, 
which is connected to the vacuum side of the fuel and vacuum pump by 
a flexible hose and pipe assembly. The cover is bolted to the body with 
sealing gaskets between them. The starting control is a flat plate with 
slotted holes. It seats on the motor cover, over the exhaust ports, and 
is held in place by a cover and flat springs. The body incloses the pad- 
dle and supports the paddle shafts. The paddle consists of two plates 
which are riveted together and carry the sealing rubber elements be- 
tween them. The sleeve, for attaching the assembly to the windshield, 
fits over one shaft which also carries the wiper arm and blade assembly. 
The opposite shaft carries the valve and valve kicker. The kicker yoke 
sets into a slot in the top of the kicker and is held by a spring which 
is attached to a retainer at its opposite end. The entire valve mecha- 
nism is inclosed by a cap which snaps onto the body casting. 

(2) Functioning. — {a) The vacuum is supplied by the fuel and 
vacuum pump and is always present when the engine is running. In 
the off position, the control button is pushed in so that the plate covers 
the exhaust ports to one side of the paddle. In this position, air can 
be exhausted only frojn one side of the paddle and atmospheric pressure 
on the opposite side forces the paddle to its "up" position and holds it 
there. 

(5) When the control is pulled out to its "on" position, the control 
plate opens the ports leading to both sides of the paddle. The valve 
located at the side of the wiper is actuated by the kicker, which oscil- 
lates with the paddle shaft, and opens and closes the exhaust ports, 



25 



TM 9-1709 
9 



ORDNANCE MAINTENANCE 



/.■ 



y. 



A' 




FRONT VIEW 




REAR VIEW 



RA PD 7429 



FiGUKE 13. — Windshield wiper assembly. 



26 



TIC 9-1709 

CHASSIS AND BODY POfi SOOUT CABS M3A1 9 

first to one side of the paddle and then to the other side in the follow- 
ing manner: Air is drawn from the body of the wiper, causing a 
partial vacuum. The atmospheric pressure behind the paddle forces 
the paddle to move to the side of the case from which the air has been 
drawn. Just before the paddle reaches the top of its stroke, the kicker 
moves the valve so that it opens the atmosphere side of the body to the 
vacuum. Air is then drawn into the former vacuum side and hence 
the paddle reverses its direction. The wiper blade arm is attached to 
the paddle shaft and this makes the blades oscillate with the shaft and 
wipe the windshield. 
(3) Specifications. 



Make 


Type 


Model 


Manufacturer's 
No. 


Ordnance No. 


White No. 


Tribo 


Vacuum 


618A 


KSB-443 


B185193 


376642 



ft. Trouble shooting. 
Symptoms and prohaMe cause 

(1) Wiper moves very slowly. 
Poor vacuum. 



Clogged exhaust ports. 
Lack of lubricant. 

Worn paddle seal (allow- 
ing air to pass by). 
AVorn cover gaskets. 

(2) Wiper moves in one direc- 
tion only. 

One set of ports clogged. 
Lack of lubricant. 

Kicker spring has per- 
manent set or is dam- 
aged. 



ProhaMe remedy 

Check lines for leaks and replace 
hose or tubing if necessary. 
Check vacuum pump for leaks 
and tighten diaphragm screws. 
Replace vacuum pump dia- 
phragm, if necessary. 

Clean ports. 

Lubricate paddle lightly with oil, 
engine, seasonal grade. 

Replace paddle assembly. 

Replace gaskets. 



Clean ports. 

Lubricate paddle lightly with oil, 

engine, seasonal grade. 
Replace spring. 



27 



TM 9-1709 

9 



ORDNANCE MAINTENANCB 



Proiaile remedy 



Symptoms and prohaMe eause 
(3) Wiper will not move. 

Hose or pipe assembly Check and replace damaged part. 

split. 
Worn pump diaphragm. Keplace diaphragm. 
Clogged ports. Clean ports thoroughly. 

Worn or damaged cover Replace gaskets. 

gaskets. 
Worn or damaged paddle Replace paddle assembly, 
seal. 
Paddle frozen in one spot. Free and lubricate lightly. 




RA FO 3338A 

PifJiiiii: 14.- Wiiiil-liielcl ^vlper installed. 

(4) Wiper streaking windshield. 

Worn or damaged wiper ' Replace blade assembly, 
blade. 

G. Removal of assembly (fig. 14.) 

(1) Remove blade and arm None, 
assembly. 

Lift blade arm and pull off spring clip. Then pull arm B185473 
out of paddle shaft hole (fig. 15(a)). 

(2) Remove motor assembly. %6"irich open-end wrench, 

28 



TM 9-1709 

CHASSIS AKD BODY FOE SOOUT CARS M3A1 9 

Detach vacuum hose from nipple. Then remove paddle shaft sleeve 
nut and washer and dismount motor assembly from top of instrument 
panel. 

d. Disassembly. — Tools: 

Pliers. Screw driver 

Long ]iose pliers. 

(1) Remove arm and blade None, 
assembly and motor assembly. 

Follow procedure given in steps c{l) and (2) above. 

(2) Eemove blade assembly. None. 

Cock blade assembly slightly and slip it out of arm slot. 

(3) Remove push button con- Pliers, 
trol. 

Pry off valve mechanism cover (figs. 15(b) and (c)). Then take 
out two screws from control cover and remove cover, springs, plate, 
pad, and button control (fig. 15(d)). 

(4) Remove motor assembly Long nose pliers, 
cover. Screw driver. 

Take out six screws holding motor cover to bodj' and remove cover. 
Strip gaskets from cover (fig. 15(e)). 

(5) Remove valve mechanism. None. 

Release spring retainer and remove spring, kicker yoke, kicker, 
spring retainer, valve, and valve washer (fig. 15(f) and (g)). 

(6) Remove paddle assembly. None. 

Lift paddle assembly straight out of body, being careful not to 
damage seal (fig. 15(h)). 

e. Maintenance. — (1) When wiper blades become worn or dam- 
aged, remove the assembly from the arm without any further dis- 
assembly, and replace with a new unit. 

(2) At the 6,000-mile check-up, disassemble the wipers, clean out 
the ports, and inspect all parts carefully. Replace any damaged or 
worn parts, lubricate the paddle, and use new gaskets for reassem- 
bling. 

When replacing the paddle, slide it into the body vertically so that 
the seals will not be damaged. 

(3) Inspect the leather washer on the inside of the windshield 
and replace if necessary. 



29 



TM 9-1709 
9 



ORDNANCE MAINTENANCE 




X. Rod w/retainer. 

B. Blade assembly. 

C. Motor assembly. 

D. Valve mechanism cover. 

E. Button control. 

F. Pad. 

G. Plate. 
H. Spring. 

.T. Control cover. 

K. Screws. 

L. Paddle and shaft assembly. 

Figure 15. — Windshield wiper assembly and disassembly. 



30 



TM 9-1709 

CHASSaS'-'iN'D BODY FOR SCOUT CARS M3A1 9 





M. Body. 

N. Cover gaskpts. 

P. Cover. 

Q. Screws. 

K. Spring retainer. 

S. Kicker yoke. 

T. Valve kicker. 

U. Valve. 

V. Spring. 

W. Felt washer. 

FiGOKE 15. — Windshield wiper assembly and disassembly — Continued. 



31 



TM 9-1709 

9 ORDNANCE MAINl'ENANCE 

(4) Inspect the rubber hoses periodically and replace them if they 
show signs of cracking. 
/. Reassembly. 

(1) Replace the paddle assein- None, 
bly. 

Slip paddle assembly into body vertically (e(2) above). 

(2) Replace the valve mecha- None, 
nism. 

Set valve washer in place. Then, in order named, replace valve, 
spring retainer, and kicker into paddle shaft. Set kicker yoke into 
slot at top of kicker, attach spring to bottom of yoke and retainer, 
and hook retaiiier to its holding pin. 

(3) Replace motor cover. Long nose pliers. 

Set gaskets on cover and replace cover and holding screws. 

(4) Replace valve mechanism None, 
cover. 

Hold cover in position and snap it in place by pushing on it. 

(5) Replace push button con- Pliers, 
trol. 

Set control in position on top of motor cover and replace pad, 
plate and springs. Fasten entire assembly with control cover and 
screws. 

g. Installation. 

(1) Attach motor assembly to %6"™ch open-end wrench, 
windshield. 

Push paddle shaft through windshield frame and fasten assem- 
bly by replacing shaft sleeve washer and nut. 

(2) Attach wiper arm to pad- None, 
die shaft. 

Push hooked end of arm into paddle shaft hole. Then set narrow 
end of arm spring clip over spring, compress spring, and push wide 
end of clip into slot cut around end of paddle shaft. 

(3) Replace wiper blade as- None, 
sembly. 

Hook blade assembly into wiper arm slot. 



32 



TM 9-1709 

CHASSIS AND BODY POiR SCOUT CARS M3A1 9-11 

Section V 
BRAKE SYSTEMS 

Paragraph 

Description 10 

Trouble shooting 11 

Service brake pedal linkage__ 12 

Master cylinder 13 

Vacuum power booster 14 

Vacuum booster air cleaner and check valve 15 

Hydraulic fluid lines and connections 16 

Wheel brakes 17 

Drive shaft brake 18 

10. Description. — a. General.— Thf: service brakes on the front 
and rear wheels are actuated under the control of a hydraulic system 
(fig. 16) which is comprised of pedal and linkage, master cylinder, 
vacuum power booster, air cleaner and check valve for booster, brake 
lines, wheel cylinders and brake shoes. The master cylinder is located 
behind the pedal linkage and the vacuum booster is located ahead of 
the linkage. Both are directly connected to the linkage. The booster 
check valve is attached to the dash on the engine side and is con- 
nected by tubing to the rear of the booster. The air cleaner is also 
attached to the engine side of the dash and is connected by tubing 
to the rear end of the booster. The brake lines connect the master 
cylinder to each of the four wheel cylinders. The wheel cylinders 
and brake shoes are inclosed by the brake drums. A disk type me- 
chanical brake for parking only is mounted on a companion flange 
of the rear propeller shaft. 

h. Functioning. — ^Pressure exerted on the brake pedal is transmitted 
by the linkage to the master cylinder. This pressure forces fluid out of 
the cylinder into the lines and thence to the four wheel cylinders. The 
wheel cylinder pistons are forced outward, thereby bringing the 
brake shoes in contact with the brake drums. The vacuum power 
unit starts to operate shortly after the pedal linkage begins to move 
and acts as a power or booster complement for the brake to actuate 
the master cylinder and reduce the amount of physical effort required 
to apply the brakes. 

11. Trouble shooting. 

Symptom cmd probable cause Probable remedy 

a. Pedal striking floor board. 

Linings worn. Readjust upper ends of shoes only. 

Incorrectly adjusted brake Readjust shoes at both ends, 
shoes. 

477229°— 42 3 33 



TM 9-1709 
11 



ORDNANCE MAINTENAN'CB 




34 



TM 9-1709 

CHASSIS AOSTD BODY FOR SCOUT OARS M3A1 11 

Symptom and probable cause Probable remedy 

Improperly adjusted pedal. Keadjust pedal linkage. 

Leak in system. Check system and repair. 

Air in system (indicated Bleed lines. 

by spongy pedal action). 

Insufficient brake fluid. Refill master cylinder. 

b. All brakes drag. 

Insufficient brake shoe Readjust shoes. 

clearance. 

Mineral oil in system. Flush system with alcohol and re- 
place cylinder cups. 

Improper pedal adjust- Readjust pedal and linkage. 

ment. 

Weak pedal return spring. Replace spring. 

c. One brake drags. 

Weakened or damaged Replace spring. 

brake shoe return spring. 
Wheel cylinder cups dis- Replace cups. 

torted. 
Shoe binding on anchor pin. Free and lubricate pin. 
Insufficient brake shoe Readjust shoes. 

clearance. 
Loose wheel bearings. Readjust bearings to position 

drum correctly around brake 
shoes. 
Grease on linings. Replace linings. Replace wheel 

bearing grease seals, if leaking, 
to prevent recurrence of trouble. 
Tubing obstructed. Replace tubing. 

d. Pulling to one side. 

Grease on linings. Replace with new linings of the 

same type. Replace wheel 
bearing grease seals, if leaking, 
to prevent recurrence of trouble. 

Shoes improperly adjusted. Readjust and check with feeler 

gage. 

Loose backing plate. Tighten plate and readjust brake 

shoes. 



36 



TM 9-1709 

11-12 



ORDNANICB MAINTENANCE 



Symptom and provable cause 
Different linings. 

Worn linings. 
Scored drums. 

e. Excessive pressure on pedal; 
poor stops. 

Brake shoes incorrectly ad- Readjust shoes, 

justed. 
Grease on linings. 



Probable remedy 

Replace linings until all are of the 

same make. 
Replace with new linings. 
Resurface or replace. 



Check 



Improper linings. 
Partial contact between lin- 
ing. 
Tubing obstructed. 

/. Light pressure on pedal, se- 
vere brakes. 



Clean or replace linings. 

wheel bearing oil seals. 
Replace with best quality linings. 
Dress down high spots on linings 

and adjust shoes at their ends. 
Replace tubing. 



Brake shoes incorrectly ad- Readjust shoes. 

justed. 

Improper linings. Replace with best quality linings. 

Partial contact between Dross down high spots on linings 

lining and drum. and adjust shoes at their ends. 

g. Noisy brakes. 

Bent or distorted backing Straighten or replace with new 

plate. plate. 

Bent or distorted brake Replace with new shoes. 

shoes. 

Dirt in linings. Remove any imbedded particles. 

Loose lining rivets. Replace loose rivets. 

Drums distorted. Replace or have reground. 

13. Service brake pedal linkage (figs. 17 and 18).^ — a. Descrip- 
tion. — The brake pedal linkage is installed in the vehicle on the inner 
left side of the frame directly behind the steering gear assembly. 

(1) Construction. — {a) The brake linkage is mounted on the clutch 
and brake pedal shaft, the middle part of which rotates in a bearing 
in the left rear engine support bracket. The shaft is internally lubri- 
cated by means of a lubricating fitting and an oil channel and has a 
key slot and a cross groove near its left end to mount and lock the brake 
pedal. To the left of the brake pedal, the bronze bushed clutch pedal 
runs free on the shaft and is retained by a plain washer, slotted nut, 



36 



TM 9-1709 

CHASaiS AND BODY FOR SCOUT GARS M3A1 12 

and cotter pin. The right-hand end of the shaft has two key slots and 
cross grooves for mounting and locking the inner and outer power 
lever clamps on either side of the power lever. 




A. Booster, vacuum, assembly BK-I6725. 

B. Hose, rubber, AQKXl. 
/Spring WI-B17472X. 

'■\ Extension WI-A12084X. 
/Spring WI-A27693X 



iL v.. 

RA PD 3234B 



D 



E. Lever WI-,34490o. 

(Fork WI-344966. 
Screw, cap, BCAXIBB. 
Nut BBBAXIB. 
Washer, lock, BECXIH. 



1 Extension WI-A23475X. 

FiGDRB 17. — Brake linkage, installed — bottom view. 



(h) The power lever is not bound to the shaft but is linked to both of 
its clamps by the power lever clamp lock pin. This pin has two cross 
grooves, and the same bolts which engage the pedal shaft grooves also 
engage the pin's grooves. Directly below this lock pin the power 



37 



TM 9-1709 
12 



OEDN'AKCB MAINTENANCE 




;W4y^|v^:- •■^&ISL/ "' 



A. Bracket assembly WI-344042. 

B. Booster assembly BK-16725. 

C. Link, drag, WI-363757. 

(Bracket assembly WI-344951. 
Stud •WI-A28584X. 
Nut BBBX24. 
Washer, lock, BECXIN. 
Fitting CLDX5A. 
fBoot WI-324634. 



B, 



\ Fitting CLDX5M. 



F. Arm assembly EG-502485. 

("Hose AQEXl. 
G J Clamp assembly CMAXIF. 

[Elbow BK-12089. 

(■Hose AQEXl. 

J Clamp CM AX IB. 

S Nipple BK-10777. 
[Elbow CPBX5BC. 
J. Yoke BK-13703. 
K. End assembly BK-13761. 



n 



FiGUKE 18. — Brake linkage, installed — side view. 



38 



TM 9-1709 

CHASSIS AND BODY FOB SCOtJT CARS M3A1 12 

lever is provided with a hole for the i-od end pin which links it to the 
master cylinder rod assembly. The shaft hole in the power lever is 
oversized and the lever is free to turn on both the shaft and the clamp 
lock pin. The resulting loose action contributes some of the free play 
desired between starting the pedal lever forward and actuating the 
booster valve. The inner power lever clamp is provided with an arm 
drilled and tapped for the two cap screws that mount the booster valve 
operating fork. Oversize holes in the fork permit adjustment. When 
assembled, the valve operating fork fits inside the fork of the power 
lever and engages the yoke end assembly of the booster valve rod. 

(c) A rod end pin connects the power lever to the booster piston rod 
yoke which fits around the integral yoke on the power lever. The 
booster valve operating fork and valve rod yoke end fit inside the power 
lever yoke. 

(2) Fwictionmg. — ^Forward motion of the brake pedal rotates the 
shaft and causes rearward motion of both power lever clamps. This 
motion is conveyed to the power lever, with slight free play, by the 
power lever clamp lock pin. When all its play is taken up, the 
power lever pushes the master cylinder piston push rod at its clevis' 
and also pulls the yoke end assembly of the booster piston valve rod, 
operating the valve after the brake pedal has moved about 1 inch. 
The vacuum power action of the booster then takes over the applica- 
tion of the service brakes for as long as sufficient pedal pressure is 
applied to keep the booster piston valve at its operating position, 

h. Removal of assembly. — The linkage cannot be removed as an 
assembly because the brake pedal shaft turns in a bearing integral 
with the left rear engine support bracket which is riveted to_ the 
chassis frame. The clutch and brake pedals and the power lever with 
its clamps must be disassembled from the shaft before the shaft can 
be removed. 

0. Disassembly of com,ponents. — Tools: 

Screw driver. ^^-mch socket wrench w/ratchet. 

%6"ij^ch open-end wrench. %6-inch socket wrench. 

1-inch open-end wrench. Drift. 

%6-inch open-end wrench. Hammer. 

Pliers. 

(1) Remove floor plate under Screw driver, 

driver's seat. 

Remove 16 self-tapping round head screws from steel floor plate 
under driver's seat. Remove plate. 

(2) Release foot dimmer switch. Screw driver. 

39 



TM 9-1709 

12 ORDNAM'CE MAESTTENANiCB 

Eemove two machine screws BCNX2CE and lock washers 
BECXIG, holding foot dimmer switch assembly DM-5530 to toe 
board and release switch. 

(3) Release throttle control shaft %6"iiich open-end wrench, 
bracket. 

Remove two bolts BAOXIAA and lock washers BECXIG holding 
left throttle control bracket WI-344332 to toe board and remove 
bracket. 

(4) Remove toe board. %6-iiich open-end wrench. 

Remove 19 lower toe board bolts BAOXlAA, BBBXIA, and lock 
washers BECXIG. Toe board now may be lifted off dimmer switch 
and off throttle control bell crank. 

(5) Disconnect master cylinder. Pliers. 

Remove cotter pin BFAXIDG and rod end pin BFFXlG holding 
rod assembly WI-344974 to power lever WI-344965. Push rod toward 
rear. 

(6) Disconnect brake vacuum Pliers, 
booster. 

Remove cotter pin BFAXIDK and rod end pin BK-13290, and 
release piston rod yoke end BK-13761 and valve rod yoke end 
BK-18762. 

(7) Remove clutch and brake Pliers, 
pedal pull-back springs. 

Unhook clutch pedal pull-back spring WI-B17472X from clutch 
relay lever. Unhook brake pedal pull-back spring extension WI- 
A23475X from power lever. Unhook vacuum booster pull-back spring 
WI-A27693X and extension WI-A12084X from booster valve fork. 
Remove springs. 

(8) Disconnect clutch pedal to Pliers, 
relay shaft double yoke. 

Remove cotter pin BFAXlDF and rod end pin BFFXIF to discon- 
nect rod WI-A43922. 

(9) Remove clutch and braka Pliers 

pedals. 1-inch open-end wrench. 

Remove cotter jjin BFAXIDK and slotted nut BBHX2C from 
left end of clutch and brake pedal shaft. Remove nut BBBXID and 



40 



TM 9-1709 

CHASSIS AOSTD BODY FOE SCOUT CARS M3A1 12 

lock washer BECXIL from brake pedal mounting bolt BAOXIDK, 
and remove bolt so that Woodruff key BCAX15A can slide in keyway. 
Tap shaft toward right side of car until stopped by Woodruff key. 
Slide clutch pedal WI-344966 off shaft and remove. Slide brake pedal 
to left, off key and shaft, and remove. 

(10) Remove oil fitting. yie-inch open-end wrench. 

Screw out lubricating fitting CLDX5M. 

(11) Remove inner power lever %6-™ch socket wrench w/ratchet. 
clamp. 

Remove cap screw BCAXlDH and lock washer BECXIL from 
clamp. Detach booster valve fork by removing two cap screws 
BCAXIBB and lock washers BECXIH. Pull inner power lever 
clamp WI-344964 off' shaft and off power lever clamp lock pin 
WI-344967. Remove key BCAX15A. 

(12) Remove power lever. Xone. 

Pull power lever WI-344966 off shaft and off power lever clamp 
lock pin WI-344967. 

(13) Remove outer power lever ^ie-^ch socket wrench, 
clamp. 

Remove cap screw BCAXlDH with lock washer BECXIL. Re- 
move power lever clamp lock pin and pull clamp WI-344962 off shaft. 

(14) Remove brake pedal shaft. Drift. 

Hammer. 

With all keys removed, drive or pull shaft out toward left side 
of vehicle. 

d. Maintenance and adjustment. — (1) Maintenance. — Keep link- 
age well lubricated and be sure that the system is clean and in cor- 
rect alinement, with no binding of the levers or shaft. 

(2) Adiustment (fig. 19). — (a) Loosen booster valve operating 
fork mounting screws. Remove master cylinder rod end pin and 
booster piston valve rod yoke end pin. Block the brake pedal in 
released position. Check clearance between power lever and pedal 
shaft at the clearance hole, making sure clearance is away from the 
driver's foot. 

(&) Adjust length of master cylinder yoke end rod to permit 
V?,2- to i/ig-inch lost motion at its clevis before it operates the mas- 
ter cylinder piston rod. Replace rod end pin and cotter pin. 



41 



TM 9-1709 
12 



ORDNAJSriCE MAINTElSrAN'OB 




Pedal, brake, WI-344959, 
Shaft, WI-344973. 

fScrew, cap, BCAXIBA. 

|Waslier, lock, BECXIH. 
„, router, WI-344962. 

i-lamp |.jjjjgp_ WI-344964. 

i Cylinder, master, assembly LO-FD-270oB. 
Screw, cap, BCBXICD. 
Nut BBBXIC. 
Washer, lock, BHCXIK. 
Switch FS-320-1. 
JLine assembly WI-S60X48, 
\Nut LO-FC-2577. 
Bracket WI^44941. 
J Hod assembly WI-344974. 
\Nut BBBX2A. 
Pin BFFXIG. 
Pin, cotter, BFAXIDG. 



RA PD 743S 



L. Lever, power, WI-344965. 



M 



{Hose AQRXl. 
Nipple BK-10777. 
Clamp CMAXIB. 
Elbow CPBX5BC. 



N. Yoke WI-312748. 
JNut BBBXIB. 
■ \ Washer, lock, BECXIM. 
Q. Booster, vacuum, assembly BK-ie725. 

("Hose AQRXl. 
R. 1 Nipple BK-12989. 

[ciamp assembly CMAXIF. 
S. Fork, valve opening, Wl-344966. 
/Cleaner, air, assembly BK-11871. 



■[Adapter BK-15419. 



Figure 19. — Brake linkage adjustment. 



42 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT GABS M3A1 13 

(c) Push vacuum booster piston rod inward, until piston bottoms. 
Aline eyes of piston rod yoke end with eyes of power lever yoke by 
adjusting cylinder position at booster engine bracket mounting. 

Note. — Always assume that valve positioning is correctly set during factory 
assembly and never alter it until a check and recheck of all other adjustments 
indicates its necessity. 

(d) Check booster piston rod end to make sure it is against rear 
sidewall of bushing in end yoke of piston valve rod, then tighten 
adjusting screws on valve operating fork, being careful not to disturb 
position of the end yoke of the valve. Make sure the valve operating 
fork centers squarely on the bushing of the piston valve rod end yoke 
to avoid binding. 

(e) If correct adjustment has been made, the valve rod should move 
y^ inch outward before any movement of the power lever occurs, with 
engine running. This can be checked by moving the brake pedal by 
hand. 

(/) Check finally, to be sure cotter pins are in place, lock nuts are 
tightened, and cap screws are secure. The foregoing adjustments, 
correctly made, plus properly adjusted brake shoes, and a clean, well 
sealed, hydraulic system, assure satisfactory operation of the hydraulic 
service brakes. 

e. Reassembly. — Tools: 

1-inch open-end wrench. %g-inch open-end wrench. 

%-inch open-end wrench. Screw driver. 

(1) Replace clutch and brake- 1 -inch open-end wrench, 
pedals on pedal shaft. 

Replace shaft in bracket bearing from left side of vehicle, replace 
key for pedal lever in its slot, raise pedal lever through toe board 
opening and slip it onto shaft over key. Push shaft toward right 
side of vehicle as far as key pei'mits, raise clutch pedal lever through 
toe board opening and slide lever on shaft. Replace plain washer and 
slotted nut and cotter pin. 

(2) Reassemble power lever with %-inch open-end wrench, 
clamps on pedal shaft. 

Insert outer clamp key in its slot in shaft, slip clamp over key, insert 
clamp lock pin in clamp so groove registers and replace mounting bolt 
and lock washer. Push power lever onto shaft and onto lock pin. 
Insert inner clamp key and push clamp on shaft over key and onto lock 
pin. Replace mounting bolt and lock washer. 

(3) Attach valve operating None, 
fork. 



43 



TM 9-1709 

12-13 ORDNANCE MAINTENANCE 

Position valve operating fork in fork of power lever, register holes 
with holes in inner clamp, insert screws with lock washers and set up 
lightly prior to adjusting. 

(4) Link power lever to master None, 
cylinder and booster cylinder. 

Seat booster valve rod yoke in valve operating fork, register bushing 
with eyes of power lever and eyes of piston rod yoke end, insert pin 
and cotter pin. 

(5) Replace lower toe board. ^^ g-inch open-end wrench 

Seat toe board so that foot dimmer switch and accelerator bell crank 
protrude through holes provided. Replace two screws and lock wash- 
ers attaching foot dimmer switch. Replace two bolts, nuts and lock 
washers attaching accelerator bell crank bracket. Insert 19 toe board 
bolts, with nuts and lock washers. 

(6) Replace floor plate under Screw driver, 
driver's seat. 

Reset steel plate, insert 16 self -tapping roundhead screws and set up 
tight. 

(7) Adjust brake linkage. 
Proceed as outlined in d{2) above. 

13. Master cylinder (figs. 20 and 21). — a. Description. — The 
master cylinder is a Wagner electric combination type unit with a 
reservoir or supply tank cast integrally with the cylinder barrel. 

(1) G onstruction (fig. 22). — (a) The supply tank is above the 
cylinder barrel and has a threaded hole on top for the combination 
filler and breather cap which maintains atmospheric pressure on the 
brake fluid at all times. An expansion plug is used to close the hole 
at the rear end of the tank. A compensating and an intake port are 
provided for fluid flow between the supply tank and the cylinder 
barrel. 

{b) On the rear left and right sides of the cylinder are two thread- 
ed holes for outlet fittings to which are attached the hydraulic brake 
lines leading to the front and rear wheel cylinders. A check valve, 
held in place by the piston return spring is installed in the rear end 
of the cylinder over the outlet port. On the front end of the return 
spring is the primary cup and piston. The cup face of the primary 
cup is against the spring, the flat face against the rear end of the 
piston. The secondary cup and its retaining ring are mounted on the 
front end of the piston and are parts of the piston assembly. A stop 
washer and its lock washer are installed to the front of the piston 



TM 9-1709 

CHASSIS AND BODY FOB SOOtJT CARS M3A1 13 




O Q H fe 



45 



TM 9-1709 
13 



ORDNANCE MAINTENAN^CE 




46 



TMC 9-1709 

CHASSIS AND BODY FOR SOOUT OARS M3A1 13 




<< m u o H 



47 



TM 9-1709 

13 ORDNANCE MArNTENANCE 

in order to limit the piston travel on the return stroke. The piston 
is actuated by the push rod assembly whose rounded end sets into a 
recess provided in the piston and whose threaded end connects with 
the brake operating linkage. A rubber boot, retained by two straps, 
covers the push rod assembly. 

(2) Functwning. — (a) The function of the master cylinder is 
to displace the fluid from a central source into the wheel cylinders. 
The master cylinder also maintains the correct volume of fluid in 
the system under all temperature conditions. The return action of 
the master cylinder after each brake application automatically super- 
charges the system and replaces fluid lost by seepage or slight leaks. 

(&) The master cylinder push rod is connected to the brake operat- 
ing pedal by an adjustable yoke and rod end pin. Depressing the 
brake pedal causes movement of the push rod, causing the master 
cylinder piston assembly to move toward the rear end of the cylinder. 
A very slight movement of the piston and cup closes the bypass port. 
When the port is closed the pressure stroke starts and as the piston 
travels toward the end of the cylinder, fluid is forced out through 
the inner part of the check valve into the hydraulic lines to the wheel 
cylinders. 

(c) When the pedal is released, the fast return of the piston cup by 
the piston return spring and the relatively slower return of fluid 
from the wheel cylinders and lines creates a vacuum in the master 
cylinder barrel. This momentary vacuum pulls additional fluid 
from the reservoir through the pistxan intake port past the lip of the 
primary cup and supercharges the system. When the brakes are in 
the "off" position, surplus fluid can escape through the compensating 
port and normalize the pressure in the system. The secondary cup 
prevents fluid from leaking out of the master cylinder into the boot, 

{d) With the piston against the stop washer, the primary cup is 
held against the piston by the piston return spring, and the compen- 
sating port should then be open. This port serves to prevent pressure 
building up in the system due to expansion of the fluid. It also serves 
to permit additional fluid to enter the cylinder to prevent shortening 
the pedal stroke due to contraction or loss of the fluid. It is important 
that this port be open when the pedal is in the release position. 

(e) A double check valve, held in the closed end of the cylinder by 
the piston cup return spring, is used to seal the cylinder to prevent air 
entering the system during the bleeding operation. The construction 
of this valve is such that fluid may be displaced into the line at very 
low pressure. Fluid passing into the lines as pressure' is applied raises 



48 



TM 9-1709 

CHASSIS AND BODY POK SOOUT CARS M3A1 13 

the smaller part of the valve from its seat and permits the fluid to flow 
to the lines. Fluid passing into the cylinder on the return stroke can 
return by raising the entire valve from its seat. When pressure on 
the returning fluid drops below 6 to 8 pounds the piston return spring 
pressure seats the valve and the system is held under slight pressure 
which serves as a seal to prevent seepage. The check valve has no 
relation to pedal movement. 
(3) Specifications. 



Make 


Type 


Manufacturer's No. 


Ordnance No. 


White No. 


Wagner Lockheed 


Combination 


LO-FE-661 


C74141 


352445 



h. Trouble shooting. 
Symptom and prohaile cause 
Pedal striking floor board. 
Leaks in cylinder. 

Insufiicient fluid. 
Clogged ports. 
Improper valve action. 
Worn primary cup. 
Worn piston. 

c. Removal of assembly (figs. 20 

Pliers. 

Hammer. 

Brass drift. 

%e-inch open-end wrench. 
(1) Disconnect master cylinder 
brake rod from linkage. Remove 
lines. 



Prol)able remedy 

Repair or replace housing and 

check fittings. 
Refill cylinder. 
Clean. 

Replace valve. 
Replace cup. 
Replace piston. 

and 21). —Tools: 

%-inch open-end wrench. 
%6-inch open-end wrench. 
Screw driver. 

Pliers. 

Hammer. 

Brass drift. 

%6-inch open-end wrench. 

i/^-inch open-end wrench. 

Remove cotter pin BFAXIDG and rod end pin BFFXIG holding 
brake rod assembly WI-344974 to power lever WI-344965. Discon- 
nect front and rear brake lines from master cylinder by removing 
front line flared tube nut LO-FC-2577 from fitting LO-FC-2832D 
and rear fine flared tube nut LO-FC-257&-E from fitting 
LO-FC-2679. 



49 



477229°— 42- 



TM 9-1709 

13 ORiDlSrANCE MAUSfTENAJStCE' 

(2) Disconnect stop light switch Screw driver. 
wires. 

Remove stop light switch wires from terminals on switch. 

(3) Remove master cylinder. %g-inch open-end wrench. 

Remove three nuts BBBXIC lock washers BECXIK and cap 
screws BCAXICD that attach master cylinder LO-FD-2705B to 
bracket Wl-344941. 

d. Disassernbly of components (fig. 23). — Tools: 

1-inch open-end wrench. %-inch open-end wrench. 

%-inch open-end wrench. Screw driver. 

(1) Remove stop light switch 1-inch open-end wrench, 
outlet fittings and filler cap. %-inch open-end wrench. 

Remove stop light switch FS-320-1 from rear of cylinder. Re- 
moye front brake line fitting LO-FC-2832 and rear brake line fitting 
LO-FC-2679 from cylinder. 

(2) Remove brake rod. %-inch open-end wrench. 

Loosen lock nut BBBX2A and unscrew yoke rod WI-344974 from 
master cylinder push rod. 

(3) Remove boot and push rod Screw driver, 
assembly. 

Remove small boot strap LO-FC-1332 and large boot strap LO- 
FC-1333 holding boot LO-FC-1331 to push rod and cylinder, and 
remove boot LO-FC-1331 and push rod assembly LO-FC-1320. 

(4) Remove working parts. Screw driver. 

Pry out piston stop washer lock wire LO-FC-1330 and remove 
stop washer LO-FC-1321, piston assembly LO-FC-1338 with sec- 
ondary cup LO-FD-1387 and ring LO-FC-3555, primary cup LO- 
FD-962, piston return spring LO-FC-1318 and double check valve 
assembly LO-FC-1266. 

e. Maintenance and adjustments. — (1) Wash all parts in clean 
alcohol. 

(2) Check bypass port and intake portholes. Holes must be 
clean. If closed, run wire through to clean. 

(3) Inspect primary cup outer edge which must be smooth and 
clean. The outer edge may have been cut by the sharp edges of the 
bypass porthole. Discard cut cup and remove sharp edges of hole 
with burring tool. 



50 



a 



i-A 



TM 9-1709 

CHASSIS AM) BODT FOR SCOUT ClARS M3A1 13 




A. Rod assembly WI-344974. 

B. Nut BBBX2A. 

C. Rod assembly LO-FC-1320 

D. Strap LO-FC-1333. 
m Boot LO-FC-1331. 

F. Strap LO-FC-1333. 

G. Wire LO-FC-1330. 
H. Stop LO-FC-1321. 
J. Piston assembly 

LO-FC-1338. 
K. Cup LO-FC-962. 
L. Spring assembly 

LO-FC-1318. 
M. Tank assembly 

LO-FC-3a64. 

t,' I Connector LO-FC-2e79. 



Gasket LO-FC-17 
R. Gasket LO-FC-20: 
S. Plug LO-FC-4073 




RA PD 



FiODEE 23. — Master cylinder — exploded view. 




RA PD 6253 

FlGUBB 24. — Master cylinder "no-go" test. 



51 



TM 9-1709 

13 OaDWANCE MAINTENANCE 

(4) Inspect cylinder bore for pitting or scratching. Walls must 
be smooth; if pitted or scratched, they may be renewed by honing. 
After honing, check the diameter with a "no-go" gage to determine 
whether or not the diameter has been enlarged excessively (fig. 24) . 
The gage should not enter the cylinder. If it does, discard the 
cylinder. 

(5) Inspect all rubber parts. If mineral oil is present in brake 
system, the parts will be enlarged and very soft. Replace primary 
and secondary cups and check valve. 

(6) Check piston fit in cylinder. 

(7) Dip all parts in brake fluid before assembly. 

(8) After assembly and installation of master cylinder in vehicle, 
bleed all brake lines as described in paragraph lQd{2). Check fluid 
level in supply tank. Level should be % to % inch from top of filler 
plug. 

(9) Service data. 

Cylinder diameter II/2 inches 

Piston clearance i 0.001 to 0.004 inch 

Piston return spring, pressure at 22%4 inches 12 pounds 

/. Reassembly of components (figs. 22 and 23). — Tools: 

Screw driver. %-inch open-end wrench. 

%-inch open-end wrench. 1-inch open-end wrench. 

(1) Replace working parts. Screw driver. 

Dip all parts in brake fluid. Install check valve, piston return 
spring, piston primary cup, piston, piston stop washer, and lock wire. 

(2) Replace boot and push rod Screw driver, 
assembly. 

Slip small end of boot over push rod and set push rod into piston 
recess. Slip large end of boot over cylinder flange and replace two 
straps on ends of boot. Allow approximately i/g-inch clearance be- 
tween end of push rod and master cylinder piston. 

(3) Replace yoke rod. yg-inch open-end wrench. 

Screw threaded end of yoke rod end nut into nut and into push 
rod. Number of turns to be made depends upon the length of pedal 
stroke required and will be determined after installation of master 
cylinder in vehicle. 

(4) Replace filler cap. fittings, 3/4-inch open-end wrench, 
and stoplight switch. 1-inch open-end wrench. 



52 



TM 9-1709 

CHASSIS AND BODY FOK SOOUT CARS M3A1 13-14 

Replace filler cap and gasket. Replace front and rear brake line 
fittings. Replace stop light switch. 
g. Installation of assembly. — Tools: 

%6-inch open-end wrench. Scre^^• driver. 

%-inch open-end wrench. Pliers. 
% 6 "inch open-end wrench. 

(1) Replace master cylinder. %(j-inch o]jen-end wrench. 

Place cylinder in position. Replace three bolts, lock washers, and 
nuts holding cylinder to bracket and tighten nuts. 

(2) Connect stop light switch Screw driver, 
wires. 

Replace wires on stop light switch wire terminal. 

(3) Connect brake lines to mas- i/2-inch open-end wrench, 
ter cylinder. %e-inch open-end wrench. 

Screw front and rear brake lines flared tube nuts into fittings on 
cylinder and tighten nuts. 

(4) Connect yoke rod to link- Pliers, 
age. 

Set yoke rod into position and insert rod end pin and cotter pin. 

(6) Bleed brakes and replace fluid. See paragraph 166^(2). 

(6) Adjust brake pedal. See paragraph 12f/(2). 

14. Vacuum power booster (fig. 25). — Ox Description. — The 
brake vacuum booster is a sliding valve, reactionary cylinder, pusher 
type unit. A reaction type unit is so connected to the master cylin- 
der and brake pedal that it supplies a maximum percentage of the 
power applied to the master cylinder. A definite proportion of the 
braking force is applied by the operator, giving him accurate con- 
trol of the total braking force and permits him to "feel" the brake 
at all times. 

(1) Construction (fig. 26). — {a) The vacuum booster cylinder or 
housing is provided with two end plates. The vacuum and atmos- 
pheric line fittings are connected to the rear plate. 

(&) The booster piston and piston rod assembly are set in the 
front end of the cylinder unit when the booster is in the released 
position. The tubular piston rod is provided with ports in the front 
and rear end for passage of vacuum and air through the sliding valve 
mechanism. 

(c) Within the tubular piston rod is a sliding plunger type valve 
having ports in the rear. 

53 



TM 9-1709 

14 



OBiDNANCB MAINTENANCE 




54 



TM: 9-1709 

chassis and body for scout cars m3a1 14 

[d) Surrounding the piston rod, on the rear end, are a cover 
filled with hair for filtering the air and a rubber guard which serves 
to receive the air from the atmospheric inlet nipple and direct it 
toward the intake ports on the rear end of the piston rod. 

(2) Functioning. — [a) With the brake in the released position 
and the engine running, the vacuum in the engine manifold draws 
the air from the booster through the check valve and creates a vacuum 
in the booster shell. This vacuum is present on both sides of the 
piston, because, in the released position, the sliding plunger type 
valve is in its extreme forward position and the front ports in the 
piston rod are so connected that air can be drawn from the front side 
of the piston as well as from the rear (fig. 27 ( A) ) . 

{h) Air from the air cleaner at atmospheric pressure enters the 
piston rubber guard through the nipple in the rear end plate and enters 
the piston rod through the port holes in the rear end of the rod. With 
the brake pedal in the released position, the front end of the plunger is 
closed oflf by the piston rod cap and by the front flange on the plunger, 
thereby preventing flow of air to the front piston face. 

(e) Depressing the brake pedal approximately 1 inch will move the 
valve rod about 14 inch toward the rear, pulling the plunger with it and 
sealing the portholes in the piston rod that lead to the front of the pis- 
ton (fig. 27(B) ). The vacuum will thereby be cut off from the front 
side of the piston. This position, with the front side of the piston 
cut off from the vacuum and the atmosphere stopped from entering 
against the front piston face, is termed the lap position. Any further 
depression of the brake pedal opens the front end of the plunger, 
through which the atmosphere can flow to the front side of the piston 
(figs. 27(C) and (D)). This differential in pressure between the 
vacuum on the rear face and the atmospheric pressure causes the 
booster piston to move toward the rear, pushing the end yoke and 
power lever toward the rear, and thereby applying pressure to the 
master cylinder push rod and actuating the hydraulic brake system. 

{d) The amount of brake application- depends upon the position 
in which the operator stops the forward motion of the brake pedal. 
When the operator stops depressing the pedal, the booster valve rod 
remains in its assumed position and does not move farther, since the 
valve rod and pedal are directly connected by the brake linkage and 
do not move independently. The piston will continue to be pushed by 
the air being admitted until the piston rod has been moved toward the 
rear a sufficient amount to move the front portholes in the piston rod 
over the plunger fiange, and thereby close off the piston front face 
from the atmosphere. The valve will then be in the lap position 

65 



TM 9-1709 
14 



OBD'N'A'NlCB MAINTENANCE 




g» ;1 



56 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 14 



I CO* '^ • lO "* 

« . . S S| . -SSS . CO 



d I ' 

W 2 ^ P 







o O H fe d W 1^' M J S 2; PL," d K tzj H P k 



57 



TM 9-1709 

14 



OKDlSrANiCE' MAINTENANCE 




58 



TM: 9-1709 

chassis and body for scout oars m3a1 14 



with both the vacuum and atjnosjjliere cut off from the piston front 
face. 

(e) When pressure is removed from the brake pedal, the valve rod is 
moved toward the front, admitting vacuum to the front side of the 
piston and cutting off the atmosphere. The vacuum balance on both 
sides of the piston is restored and the brakes are released. 

(3) 8'pecif.cations. 



Make 


Model 


Manufacturer's 
No. 


Ordnance 

No. 


White No. 




RP66 


BK-16725 


D33796 


D17799 







h. Trouble shooting. 
Symptom and probable cause 

Excessive pedal pressure. 
Leak in booster. 

Improper valve action. 

Worn valve plunger. 

Leaky check valve. 

Clogged air cleaner. 
c. Removal of assembly (fig. 25) . 
(1) Disconnect vacuum line. 



Probable remedy 

Replace end plates, cylinder pack- 
ing ring, or piston felt and 
packing. 

Adjust. 

Replace plunger. 

Replace check valve stem or gasket 

Clean. 

Screw driver. 



Loosen screw in clamp CMAXlF holding hose WI-A43843X to 
booster and remoA'e hose from nipple WI-A31053X. 

(2) Disconnect air cleaner line. Screw driver. 

Loosen screw in clamp WI-A29802 holding hose WI-348798 to 
booster and remove hose from nipple WI-A31053X. 

(3) Disconnect front end of Pliers, 
booster. 

Remove cotter pin BFAXlCD and rod end pin BFFXIG holding 
booster yoke to yoke WI-312748 on engine bracket. 

(4) Disconnect rear end of Pliers, 
booster. 

Remove cotter pin BFAXlCD and rod end pin BK-13290 holding 
booster yoke end assembly BK-13761 to power lever WI-344965. 
Remove booster assembly. 

59 



TM 9-1709 

14 OEiDNANCE MAINTENANCE 

d. Disassembly, (fig. 28). — Tools : 

%6"iiich socket wrench. 1-inch open-end wrench. 

%-inch open-end wrench. Screw driver. 

11/4-inch open-end wrench. Pliers. 
%-inch open-end wrench. 

(1) Remove front end stud v^ g-inch socket wrench, 
plate. 

Eemove four nuts BBBXIA and lock washers BECXlG holding 
four hook studs BK-15511 to stud plate BK-16749. and remove studs 
and plate. 

(2) Eemove piston and rod None, 
assemblj' from booster. 

Slide piston assembly BK-16750 and rear end plate and guard out 
of booster cylinder assembly BK-16754. Remove rear end plate gasket 
BK-16738. 

( 3) Eemove piston from rod. %"iiich open-end wrench. 

1^-inch open-end wrench. 

Set piston assembly in radius block or in vise and remove piston 
rod cap BK-15176, and seal BK-14006 from front end of piston. 
Eemove nut BK-16735 holding piston to rod. In the order listed, 
remove following parts from piston rod: piston felt retainer 
BK-16739, ring BK~16751, felt assembly BK-16737, front plate 
BK-16740, oil wick BK-16736, rear plate BK-16742, and nut 
BK-16735. 

(4) Eemove rear end plate Screw driver, 
assembly. 

Remove three machine . screws BCNX2AC and lock washers 
BECXlG holding dust cover BK-16800 to rear end plate. Remove 
rear end plate w/bushing assembly BK-16746 by sliding off front 
end of piston rod. Eemove cover gasket BK-16734. 

(5) Disassemble rear end plate Screw driven, 
and seal. 

Eemove end plate spring BK-10033, washer BK-10031 and seal 
BK-10550 from end plate. If necessary, the end plate bushing 
BK-16744 can be pressed or driven out of the end plate. 

(6) Eemove dust cover. None. 



60 



TM 9-1709 

CHASSIS AND BODY POiR SOOUT OARS M3A1 14 

Slip end of rubber guard off flange on dust cover BK-16800 and slide 
cover off piston rod. Remove felt BK-^15400 from piston rod. 

(7) Remove piston rod rubber None. 
guard. 

Slip end of guard BK-15380 off flange on end yoke and remove 
from piston rod. 

(8) Remove valve rod yoke end- %-inch open-end wrench. 

Note number of threads extending back of hexagon nut. Back 
off nut BK-14077 far enough to allow the trunnion holding clip 
BK-18768 to be slipped back off the trunnion. After the clip is 
removed, the two valve rod yoke ends BK-13762 can be removed from 
the side of the trunnion. Unscrew trunnion BK-13763 from valve rod 
and remove clip and adjusting nut. Slip off valve rod guard BK-13866. 

(9) Remove piston rod end yoke 1-inch open-end wrench, 
and nut. 

Note number of threads on piston rod extending through end yoke. 
Unscrew end yoke BK-13703 and remove nut BK-13706. 

(10) Disassemble valve rod and Pliers, 
plunger (fig. 29). 

After removal of the valve rod yoke end and adjusting nut, and 
the piston rod front cap and seal, the valve assembly can be slipped 
out of the piston rod. Remove plunger pin BK-13980' and detach 
plunger BK-15253 from valve rod BK-15174. Remove valve rod 
spring BK-15255 and spring washer BK-15258 from the rear end of 
the piston rod. Remove snap ring BK-13772, felt BK-13770, and felt 
retainer BK-18768. 

e. MainteTMTice cmd adjustments. — (1) Inspect all rubber parts and 
replace if torn or swollen. 

(2) Inspect piston felt and packing and replace if torn or shredded. 

(3) Inspect rear end plate. Replace or rebush if sprung enough 
to cause leaks. 

(4) Inspect piston plates and replace if bent. 

(5) Inspect rear end plate packing ring and replace if torn. 

(6) Inspect piston rod seal and replace if worn. 

(7) Inspect valve rod and plunger. If plunger is worn, replace 
with new unit. 

(8) Lubricate piston felt before assembly. 

(9) Lubricate parts of valve rod which slip through valve rod 
guide before assembly. 

61 



TM 9-1709 

14 



ORiDN'ANICB MAINTEKANCB 




62 



TM 9-1709 

CHASSIS AND BODY rO« SCOUT OARS M3A1 14 



-c^- g|6 



kj . . <d «' d H fa d ffi H-' M 'j ^ 1^' ai C? oj r/ 



■< fd d O H fa d S Hi M 4 S ^i &; d « ai ti d p>' 



63 



TM 9-1709 

14 



ORDNANCE MArNTETCANCE 




64 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 14 

(10) Lubricate booster with 2 ounces of oil, engine, SAE 10, after 
assembly. 
/. Reassemhly (figs. 28 and 29). — Tools: 

Pliers. 

1-inch open-end wrench. %-inch open-end wrench. 

%-inch open-end wrench. Press. 

1%-inch open-end wrench. %6-inch socket wrench. 

(1) Assemble valve rod. Pliers. 

Eeplace felt retainer, felt, and snap ring in rear end of piston rod. 
Replace valve rod washer in piston rod. Set ball of valve rod into 
plunger, replace plunger pin, and after setting valve rod spring on 
rod, replace entire assembly into piston rod. 

(2) Eeplace piston rod end yoke 1-inch open-end wrench 
and nut. 

Eeplace nut on rear end of piston rod. Screw end yoke on and 
note number of threads extending through yoke. After setting 
number of threads, tighten up nut against yoke. 

(3) Eeplace valve rod yoke end. %-inch open-end wrench. 

Eeplace valve rod guard. Screw adjusting nut on rear end of valve 
rod and replace trunnion holding clip. Screw trunnion or rod, set 
two valve rod yoke ends on sides of trunnion and move the clip forward 
to hold the ends on the trunion. Tighten adjusting nut and check 
the number of threads extending back of the nut. 

(4) Eeplace piston rod rubber None, 
guard. 

Slip the end of the guard onto the front end of the piston rod and 
onto the piston rod end yoke flange. 

(5) Eeplace dust cover. None. 

Eeplace felt on piston rod. Eeplace dust cover on rod and slip 
piston rod guard over cover flange. 

(6) Eeassemble rear end plate Press, 
and seal. 

Press bushing into end plate if it has been removed. Eeplace seal, 
washer and spring in end plate. 



65 

477229°— 42 5 



TM 9-1709 

14 ORDNANCE MAINTENANCE 

(7) Replace rear end plate. None. 

Slip plate on piston rod and replace three machine screws that 
hold dust cover to end plate. 

(8) Replace piston on rod. %-inch open-end wrench. 

1%-inch open-end wrench. 

Replace piston nut on front end of rod. Replace rear piston plate, 
oil wick, front plate, felt, ring, and felt retainer. Replace piston nut. 
and the piston rod front cap and seal. 

(9) Replace piston and rod as- None, 
sembly. 

Slide entire piston and rod assembly into booster cylinder. 

(10) Replace front end plate. ^g-iJ^ch socket wrench. 

Set four hook studs and end plate in position and replace four nuts 
and lock washers on studs. 
g. Installation of assembly. 

(1) Connect rear end of booster. Pliers. 

Set booster in position and replace rod end pin and cotter pin holding 
booster end yoke to power lever. 

(2) Connect front endof Pliers, 
booster. 

Replace rod end pin and cotter pin holding booster to yoke on engine 
bracket. 

(3) Connect vacuum end air Screw driver. 
lines. 

Replace hoses on nipples on booster and tighten hose clamps. 

(4) Adjust linkage. 

Proceed as outlined in paragraph 12d. 

h. Test. — (1) Remove filler pipe plug in booster front end plate and 
connect in a vacuum gage. 

(2) Start the engine and note the reading on the gage. It should 
show a vacuum of 17 to 20 inches. Stop the engine and note if 
vacuum is retained for a reasonable length of time. If the gage 
shows a rapid falling ofl' (more than 10 inches in 10 seconds) , it indi- 
cates a leak in the cylinder, vacuum line, check valve, or inlet mani- 
fold connector. Leakage in the vacuum booster may often be 
corrected by a thorough lubrication of the unit. 



66 



TM 9-1709 

CHASSIS AND BODY POE SOOTJT OARS M3A1 14 



Z^'^^'^?:::-.. 




A. Line asseml)ly WI-352223. 

( Valve assembly BK-16864. 
„ Screw, cap, BCBXIAB. 
Nut BBBXIA. 
Washer, lock, BECXIG. 
C. Elbow WI-A23847X. 
Nipple WI-A38829X. 
Plug WI-A9203X. 
Pipe assembly WI-352225. 
Clip WI-A14193X. 
Screw, cap, BCBXIAA. 
Nut BBBXIA. 
Washer, lock, BBCXIG. 



D 



«{ 



Bracket BK-1G819. 
Screw BCBXIAA. 
Nut BBBXIA. 
Washer, lock, BECXIG. 

Cleaner assembly BK-11871. 

Adapter BK-15419. 

Screw, machine, BCNX2AE. 

Nut BBKX2C. 

Washer, lock, BECXIE. 

Hose AQRXl. 

Clamp CMAXIB. 

Hose AQRXl. 

Clamp CMAXIF. 



FiGOEE 30. — Brake vacuum booster check valve anij air cleaner, installed. 



67 



TM 9-1709 

16 ORDNANCE MAINTENANCE 

15. Vacuum, booster air cleaner and check valve (fig. 30). — 
a. Air cleaner. — 

(1) Desori'ption. — The remote air cleaner is designed to filter the air 
entering the vacuum booster cylinder. It is mounted on the dash 
at the left side of the engine compartment and is connected to the 
booster cylinder air intake by a tube. 

(2) Specifications. 



Make 


Manufacturer's No. 


Ordnance No. 


White No. 


Bendix _ _. _- __ 


BK-11871 


A167685 


A43905 







(3) Removal of assembly. 

Air cleaner removal. Screw driver. 

%-inch open-end wrench. 
Loosen and remove two nuts BBKX2C, lock washers BECXIE, 
and screws B,CNX2AE that attach adapter BK-154:19 to bracket. 
Loosen hose clamp and slip off hose. Remove air cleaner assembly. 

(4) Disassembly of components. 

Disassemble air cleaner. Screw driver. 

1%6-iiich open-end wrench. 

Pry off snap ring BK-11873. Lift off cover BK-11848. Take out 
hair BK-11192 and remove stud BK-11872 from cleaner BK-11391. 
Unscrew adapter BK-15419 from stud. 

(5) Maintenance. — Wash hair thoroughly in solvent, dry-cleaning, 
dry and saturate with oil, engine, SAE 10. Clean out all holes before 
reassembly. 

(6) Reassembly tif components. 

Reassemble air cleaner. Screw driver. 

i54g-inch open-end wrench. 
Screw stud into adapter and tighten. Place cleaner on stud. Re- 
place hair. Put on cover and snap lock ring into place. 

(7) Installation of assembly. 

Replace air cleaner. Screw driver. 

%-inch open-end wrench. 

Place adapter on bracket lining-up screw holes. Replace screws, 
lock washers and nuts and tighten. Replace hose and tighten hose 
clamp. 

b. Check vahe {fig. ^0). — (1) Description. — ^A check valve mounted 
on the dash at the right side of the engine compartment is provided 

68 



TM 9-1709 

CHASSIS AND BODY FOR SCOTJT CARS M3A1 15-16 

in the vacuum line of the brake booster between the engine intake 
manifold and the power cylinder vacuum outlet. The function of 
the check valve is to seal the vacuum in the power cylinder when the 
engine stalls. If the engine should stall, the check valve will drop to 
its closed position, thereby holding a vacuum in the cylinder which 
will be sufficient to provide at least one maximum power brake 
application. 

(2) Specifications. 



Make 


Manufacturer's No. 


Ordnance No. 


White No. 


Bendix _ _ . 


BK-16864 


A167374 


A33439 







(3) ReTTioval of assembly. 

Remove check valve. 
%-inch open-end wrench. %6"iiich open-end wrench. 

Loosen and remove two flared tube nuts WI-SSTXS from check valve 
BK-16864 inlet and outlet fittings. Loosen and remove two bolts 
WI-S2BX2, lock washer WI-S4BX7, and nuts WI-S38X1 from 
bracket BK-16819 ; mount check valve to dash and remove valve. 
- (4) Disassembly of com^ponents. 

Disassemble check valve. Screw driver. 

Remove elbow WI-A23847X and nipple WI-A33829X. Slide rub- 
ber bracket off valve. Remove four machine screws BK-61-S41 and 
lock washers BECXIE and remove valve cap BK-16645 and gasket 
BK-16640. Lift valve stem assembly WI-364629 out of valve body 
BK-16639. 

(5) Maintenance. — Inspect valve stem and replace if bent or worn. 

(6) Reassembly of components. 

Reassemble check valve. Screw driver. 

Replace valve stem in body and replace gasket, cap, screw, and lock 
washers. Slip rubber bracket over body and replace flared tube fittings. 

(7) Installation of ossemMy. 

Replace check valve. %-inch open-end wrench. 

Set valve in place and replace two bolts, nuts, and lock washers. 
Connect vacuum line flared tube nuts to fittings. 

16. Hydraulic fluid lines and connections (flg. 16). — a. De- 
scription. — (1) Two main fluid lines for the hydraulic service brake 



69 



TM 9-1709 

16 



OKDlSrANiCE MAINTE'N'ANCE 



system start respectively from the left and right outlet fittings of the 
master- cylinder, which is mounted inside of the frame rail on the 
master cylinder bracket. The 14-inch pipe which feeds the front wheel 
brake lines starts from the left hand outlet fitting of the master 
cylinder, passes through the frame, and runs along the inside of the 
frame to the tee inlet fitting. The line is held by clips attached to 
the frame, as is the tee. The tee has two outlet openings, one facing 
forward and the other toward the rear. The inverted flared tube nut 
at the end of the left wheel cylinder pipe screws into the rear opening 




HOSE, ASS'Y-B184318 



RA PD 6250A 



Figure 31. — Front wheel brake line connection at frame. 



and connects the pipe to the tee. The pipe then runs backward along 
the inside of the frame rail until it is approximately opposite the wheel 
cylinder, at which point it is connected to the wheel cylinder flexible 
hose fitting by means of another inverted flared tube nut. The flexible 
hose fitting is a special type (fig. 31) which passes through the frame 
from the wheel side and is attached to the frame. The flexible hose 
completes the line from the tee to the left wheel cylinder, where it 
screws into the cylinder inlet fitting. 

(2) The inverted flared tube nut at the end of the pipe leading to the 
right-hand wheel cylinder screws into the front end of the tee. After 
leaving the tee, the pipe crosses to the right-hand frame rail, along the 

70 



TM 9-1709 

CHASSIIS AND BODY FOR SOOUT OARS M3A1 16 

front cross member of the frame, and then runs backward along the 
inside of the frame rail to a point opposite the wheel cylinder. At 
this point it is connected to the wheel cylinder flexible hose fitting in 
the same manner as the left-hand pipe. The pipe is held by three clips 
bolted to the front cross member. It is connected to the right-hand 
wheel cylinder by a flexible hose similar to the one used on the left side. 

(3) The ^^ig-inch feed pipe for the rear brakes is attached to the out- 
let fitting on the right side of the master cylinder. It then passes 
through two rubber grommets in the frame cross member gusset and 
runs back along the inside of the frame rail to the rear hose bracket, 
which is bolted on the frame. The pipe is secured by clips bolted to 
the frame rail. The pipe is connected to the rear flexible hose union 
by means of an inverted flared tube connector in the same manner used 
in connecting to front wheel cylinder hose fittings. The flexible hose 
fitting, in this case, passes through the bracket from the rear and is 
fastened to the bracket. The flexible hose connects to the rear tee by 
threading the hose nipple into the tee's top opening. The tee is bolted 
to the rear axle housing. The left- and right-hand outlet openings of 
the tee are connected to the left and right rear wheel cylinder inlet 
fittings by two 14 -inch pipes threaded into the tee by means of two 
inverted flared tube nuts. The ends of the pipes going to wheel 
cylinders are screwed on to their respective connectors by flared tube 
nuts. 

h. Trouble shooting. 

Symptom and probable cause Probable remedy 

(1) Loss of fluid in system. 

Loose connection. Retighten. 

Damaged flared tube end. Straighten with flaring tool or 

replace tube. 
Ruptured tube or hose. Replace. 

(2) Failure of one or more wheel brakes to operate. 

Plugged flexible hose. Clear hose if possible, or replace. 

Plugged tube. Replace. 

c. Removal of assemblies. — Tools : 

%6-i"'^li open-end wrench, %-inch open-end wrench. 
i%e-inch open-end wrench, %-inch open-end wrench. 
1/2-inch open-end wrench. %g-inch open-end wrench. 

(1) Remove front wheel cylin- %6"iiich open-end wrench. 
der hose assemblies. i%e-inch open-end wrench. 



71 



TM 9-1709 

16 OKlDWANCB MAINTENANCE 

Disconnect flared tube nuts WI-30828X at frame ends of hoses. 
Disconnect each hose fitting from frame by removing holding nut 
and lock washer. Remove hose assemblies LO-FC-3551B from wheel 
cylinder inlet connector LO-FC-672 by unscrewing hose nipples 
WI-A-13620X. 

(2) Remove ,line assembly, %6-inch open-end wrench, 
(front tee to left-hand wheel). 

Disconnect inverted flared tube nuts WI-30828X at tee LO-FC~ 
3048 and at hose fitting and drop line assembly WI-S69X5. 

(3) Remove line assembly, yig-inch open-end wrench, 
(front tee to right-hand wheel). 

Disconnect inverted flared tube nuts WI-30828X at tee and at hose 
fitting. Detach clips WI-A27593X, holding line assembly WI- 
S69X56 to frame, and lower assembly. 

(4) Remove line assembly %6-inch open-end wrench, 
(master cylinder to front tee) . 

Disconnect inverted flared tube connectors LO-FC-2832 (front), 
LO-FC-2679 (rear), at tee and master cylinder outlet fitting and 
lower line assembly WI-S69X48. 

(5) Remove front tee. ^-inch open-end wrench. 

Take out bolt BCBXIBA, nut BBBXIB and lock washer BECXIH 
holding tee LO-FC-3048 to frame. 

(6) Remove line assembly, i^^-inch open-end wrench, 
(master cylinder to rear hose con- 
nection) . 

Disconnect flared tube connectors LO-S-FB-1079B at master 
cylinder rear outlet fitting and at rear hose fitting. Detach clip 
WI-A27593X holding line assembly WI-S70X60 to frame, draw 
assembly through two rubber grommets WI-A10766X and remove. 

(7) Remove hose assembly, %-inch open-end wrench, 
(rear connection to axle tee). %-inch open-end wrench. 

%6-inch open-end wrench. 

Remove nut WI-A28153X and lock washer BECX2P holding hose 
fitting to bracelet WI-344941. Disconnect hose assembly WI-A35814 
at tee and lower assembly. 

(8) Remove line assembly %g-inch open-end wrench, 
(rear axle tee to left-hand ^^jg-inch open-end wrench, 
wheel) . 

72 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 16 

Disconnect inverted flared tube nut WI-A308281X at tee and 
flared tube nut WI-B17384X at wheel cylinder and remove line 
assembly WI-S72X9. 

(9) Eemove line assembly yie-inch open-end wrench, 
(rear axle tee to right-hand %6-in^ch open-end wrench, 
wheel) . 

After removing bolt TD-3X82, nut BBBXID, and lock washer 
BECXlL which hold pipe clip to differential housing, remove cap 
screw BANXlCA and lock washer BECXlK holding remaining pipe 
clip to axle housing and proceed as in (8) above. 

(10) Kemove rear tee. %-inch open-end wrench. 

After removing line connections at tee, take out cap screw 
BANXICC and lock washer BECXlK holding tee WI-A35811X 
to housing. 

d. Maintenance. — (1) Fife assemblies. — ^Very little maintenance is 
required on the hydraulic lines since damaged parts can usually be 
I'eplaced as assemblies. However, if no pipe assemblies are available, 
they can be made as follows: 

{a) Cut a straight piece of steel tubing to the required length, 
using cutter shown in figure 32. It is very important that the tubing 
be cut at right angles to its length, since it is to be flared. 

{b) Eemove the bur left inside the tubing. Use the reamer attached 
to the cutting tool or the reamer furnished with the flaring tool. 

(c) Cut the pipe assembly which is to be replaced and remove the 
end fittings. 

{d) Place each fitting on the end of the new tube which is to be 
flared and clamp the end of the tube in the flaring tool (fig. 33) . 

(e) Form the flare by using the mandrel. 

(2) Bleeding the line. — Bleeding the line consists of displacing 
ail the air which may have accumulated in the system with the fluid. 
It is done by forcing the fluid through the lines until it flows from 
the bleeder valve on each of the four wheel cylinders in a solid 
stream. This is necessary only when some part of the hydraulic 
mechanism has been disconnected or the fluid in the supply tank 
has become too low. For refilling, use only fluid, brake, hydraulic. 
Proceed as follows: , 

{a) Remove the two screws holding the floor plate over the master 
cylinder filler plug and remove plate. 

(6) Unscrew the filler plug on top of the tank. 



73 



TM 9-1709 
16 



ORDNANCE MAINTENANCE 



r CUTTER WHEEL 




REAMER 



EXTRA CUTTER WHEELS AND PIN 
RA PD 6230 



FiouRE 32. — Pipe cutter and reamer. 




RA PD 6229A 



FiGUUE 33. — Pipe flaring tool. 



74 



TM: 9-1709 

chassis ant) body foe scout cabs m3a1 16 

(c) Using a Wagner Lockheed fluid filler, insert nozzle into filler 
hole as shown in figure 34. 

(d) Starting with the wheel cylinder farthest from the master 
cylinder, remove the bleeder valve cap screw. After this the nipple 
at the end of the rubber drain tube may be screwed in place (fig. 35) . 

(e) Slide the bleeder valve wrench over the rubber tube. Place 
the free end of the tube below the level of the brake fluid in a clean 
glass container comparable to a 1-pint jar. 

(/) Open the valve three-quarters of a turn. 

(ff) Slowly depress the foot pedal a number of times until fluid 




Figure 34. — Hydraulic brake system fluid replacement. 

issues from the end of the tube in a solid stream without air bubbles. 
Allow the return spring to return the pedal to its release position. 

(A) After a cylinder has been bled, do not again depress the brake 
pedal until the valve of the next cylinder is opened; otherwise air 
may be forced over from a line yet to be bled to a line on which this 
operation has been completed. 

75 



TM 9-1709 
16 



O-RDNAJSfOB MAINTENANCE 



(i) Follow around all four brake cylinders and when this has been 
completed remove the fluid refiUer from the supply tank and replace 
the filler plug and floor plate. 

e. Installation of assemblies. — Tools: 



%-inch open-end wrench. 
% 6-inch open-end wrench. 
%6-iiich open-end wrench. 
%-inch open-end wrench. 
i%g-inch open-end wrench. 



1/2-inch open-end wrench, 
inch socket wrench. 



1%6 



•/1 6-inch socket wrench. 



7Z 



%-inch socket wrench. 




B^iGUKE 35. — Hydraulic bralce system bleeding operations. 

(1) Replace rear axle tee. %-inch open-end wrench. 
Secure tee to axle housing with lock washer and cap screw. 

(2) Replace line assemblies to %e-inch open-end wrench, 
rear wheel brake cylinders. '^'Jg-inch open-end wrench. 

Connect one end of each assembly to the tee by means of its in- 
verted flared tube nut. Then connect opposite ends to wheel cylinder 

76 



TM 9-1709 

CHASSIS Xm) BODY FOR SOOIIT OARS M3A1 16-17 

fittings with the flared tube nuts. Fasten right-hand pipe clip to 
frame. 

(3) Keplace rear flexible hose, %-inch open-end wrench. 

%-inch open-end wrench, 
i^ie^inch open-end wrench. 

Connect one end of hose to tee hj means of its inverted flared tube 
nut and fasten fitting at opposite end to bracket with lock washer 
and nut. 

(4) Replace line assembly (mas- i^-inch open-end wrench, 
ter cylinder to rear hose connec- 
tion) . 

Pass line through grommets in frame. Connect one end of line to 
rear hose fitting and the opposite end to master cylinder fitting by 
means of its inverted flared tube nuts. Fasten pipe clip to frame. 

(6) Eeplace front tee. None. 

Secure tee to frame with bolt and lock washer. 

(6) Replace line assembly (mas- ^g-inch open-end wrench, 
ter cylinder to front tee). 

Connect one end of assembly to master cylinder outlet fitting and 
opposite end to tee. Fasten three pipe clips to frame. 

(7) Replace front wheel brake iS/^g-inch socket wrench, 
flexible hose assemblies. ^g-inch socket wrench. 

%-inch socket wrench. 

Connect assemblies to each front wheel cylinder inlet. Insert spe- 
cial fitting, at opposite end of each hose, through frame and secure 
it with lock washer and nut. 

(8) Replace line assemblies ^g-inch open-end wrench, 
(tee to left- and right-hand 

wheel) . 

Connect one end of each assembly to tee by means of its inverted 
flared tube nut. Then connect opposite end of each assembly to 
right- and left-hand wheel hose fitting in the same manner. Fasten 
the three right-hand pipe clips to frame. 

17. Wheel brakes (fig. 36). — a. Description. — -The wheel brakes, 
front and rear, are of the conventional, hydraulic, two-shoe, internal 
expanding type. They operate within brake drums of special gun 
iron which has high wear resistance. 



77 



TM 9-1709 

17 



ORDNANCE MAINTENANCE 




A. 
B. 
C. 
D. 
E. 



C-washer. 
Anchor pin. 
C-washer. 
Return spring. 
Link. 



RA PD 33611 



F. Wheel cylinder. 

G. Cam. 

H. Backing plate. 
I. Brake shoe. 

Figure 36. — Wheel brake assembly, installed. 



78 



TM 9-1709 

CHASSIS AJSTD BODY FOR SCOUT CARS M3A1 17 

(1) Construction (fig. 37). — {a) Each brake shoe is a T-sectioned 
steel casting with a lining riveted to the outside periphery. The shoes 
are anchored on the brake backing plate at the lower or "heel" end 
on eccentric anchor pins and are retained by plain washers and 
C-shaped washers which set into grooves in the pins. The anchor 
pins carry felt oil washers in retainers behind the shoes and the pins 
are locked by nuts and lock washers at the rear of the brake backing 
plate. Each shoe has two guide slots which fit over guide pins 
riveted into the brake backing plate. The shoes are supported on 
the pins by coil springs surmounted by plain washers. The shoes are 
held on the guide pins by plain washers and C -washers the same as 
on anchor pins. The upper or "toe" ends of the shoes are recessed 
to accommodate the clevis pins of the wheel cylinder connecting 
links. The shoes are held against adjusting cams by means of a re- 
turn spring, the ends of which are hooked into the upper guide 
slots. The adjusting cams are riveted to their rotation pins, which 
are held, as placed, bj^ friction coil springs between cams and backing 
plate. The cams are adjusted by means of the hexagon-head pins 
which are rotated from the rear of the backing plate. 

(&) The wheel brake cylinder housings (fig. 38) are cast iron and 
each is bolted to the top of its respective brake backing plate by two 
cap screws and lock washers. A boss on the rear of each cylinder is 
drilled and tapped with one hole for the brake hose fitting and with 
another hole for the bleeder valve fitting. Each cylinder assembly 
consists of a piston' spring, two rubber cups, two pistons, two rubber 
boots, and two connecting links with riveted yoke and pins. The 
spring is located in the center of the cylinder with a cup fitted over 
each end. The pistons are a close fit and are installed with their flat 
end against the cups. The rubber boots fit over the ends of the cylinder 
housing and snap into grooves cut around the outside of the housing. 
The connecting links pass through holes in the center of the boots and 
seat in a spherical cup in each piston. The yoke ends rest in the brake 
shoe recesses and are held there by brake shoe return spring pressure. 

(2) Functioning . — Fluid forced out of the master cylinder passes 
through the lines into the brake cylinders and exerts its energy against 
the pistons. This causes the pistons and connecting links to move 
outward. The rods push the brake shoes at their upper ends, making 
them pivot on their anchor pins and causing brake linings to be forced 
against brake drums. When the pressure is released at the brake pedal, 
the brake shoe return spring pulls the shoes back to their original posi- 
tion. This forces the pistons back into the cylinder, which in turn 
forces fluid out of the cylinder and back through the lines to the master 

79 



TM 9-1709 

17 



ORDNANCE MAINTENANCE 



?^r7F=^ 




80 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT C3ARS M3A1 17 




81 



477229° — 42- 



TM 9-1709 

17 



ORDNAKCE MAINTENANCE 



cylinder. Brake shoes can be set closer to or moved away from the 
drums by turning the adjusting cam bolts. Excess side play of the 
shoes is prevented by the guide pins. 
(3) Sfediioations. 



Make 


Type 


Model 


Manufacturer's No. 


Ordnance 

No. 


White 
No. 


Wagner 


Internal 


Hydraulic 


LO-FF-913, front, 


D34136 


326910 


electric. 


expand- 
ing. 


two-shoe. 


left-hand. 
LO-FF-914, front, 

right-hand. 
LO-FC-3378, rear, 

left-hand. 
LO-FC-3379, rear, 

right-hand. 




326911 



Service brake type Four drum hydraulic. 

Wheel cylinder, front 1% inches 

Wheel brake shoes, front : 

Size 15 X 214 inches 

Lining area (square inch per axle) 131 inches 

Length (forward) ^^Viq inches 

Length (rearward) ISiy^g inches 

Width 21^ inches 

Thickness % inch 

Wheel cylinder, rear li^ inches 

Wheel brake shoes, rear: 

Size 15 X 214 inches 

Lining area (square inch per axle) 128% inches 

Length (forward) 16% inches 

Length (rearward) 12%6 inches 

Width 214 inches 

Thickness 14 inch 

h. Trouble shooting. 

Symptoms and prohable cause ProhaUe remedy 

(1) Pedal goes to floorboard. 

Normal wear of linings. Readjust upper ends of shoes only. 
Brake not properly adjusted. Adjust shoes at both ends. 

(2) All brakes drag. 

Mineral oil in system. Flush system with alcohol and re- 

place wheel cylinder cups. 
InsuiEcient brake shoe clear- Eeadjust shoes, 
ance. 



TM 9-1709 

CHASSIS AND BODY FOiR SCOUT OARS M3A1 17 

(3) One brake drags. 

Weak brake shoe return Replace spring. 

spring. 
Brake shoe binding on an- Free and lubricate pin. 

chor pin. 
Brake shoe set too close to Readjust shoes to proper clearance. 

drum. 
Wheel cylinder cups dis- Replace cups. 

torted. 

(4) Car pulls to one side. 

Worn linings. Replace with new linings. 

Grease soaked lining. Replace with new lining of same 

type. 

Loose backing plate. Tighten plate and i-eadjust brake 

shoes. 

Shoes improperly adjusted. Readjust shoes to proper clear- 
ance. 

Different makes of linings. Replace those differing with lin- 
ing of same make. 

Scored drums. Resurface or replace. 

(5) Springy, spongy pedal. 

Brake shoes not properly Readjust shoes. 

adjusted. 
Air in system. Bleed system at wheel cylinders. 

(6) Excessive pressure on ped- 
al, poor stop. 

Brake shoes not properly Readjust shoes. 

adjusted. 
Improper lining. Replace with best quality lining. 

Grease on lining. Clean or replace lining. 

Lining making partial con- Remove high spots. 

tact. 

(7) Light pressure on pedal, 
severe brakes. 

Brake shoes not properly Readjust shoes to proper clear- 
adjusted, ance. 
Grease soaked lining. Replace with new lining of same 

make. 



83 



TM 9-1709 

17 ORDNANCE MAINTENANCE 

G. ReTTioval of assembly. — (1) Brake shoes. — Tools: 

Wheel stud nut wrench. Chisel. 

Jack. Puller. 

%-inch socket wrench. Wheel cylinder clamp. 

iyi6-inch open-end wrench Special spring pliers. 

Wheel bearing nut wrench Screw driver. 
Hammer. 

{a) Remove wheel and tire Wheel stud nut wrench, 

assembly. Jack. 

Loosen wheel stud nuts BW-37889E (left-hand), BW-37888E 
(right-hand). Then jack up and block wheel assembly which is to be 
worked on, so that tire is just off ground. Eemove wheel stud nuts 
and pull off wheel assembly. This may be made easier by slipping 
a greased board under tire and sliding assembly off studs onto board. 

(&) Remove hub and drum as- 
sembly. 

%-inch socket wrench. Hammer. 

i^i/i(j-inch open-end w-rench. Chisel. 

Wlieel bearing nut wrench. Puller. 

Remove drive flange assembly TD-A-1-3870-B-2 from front axle 
or remove axle shaft assembly TD-A-1-3202-C-1255 from rear axle. 
Then remove wheel bearing lock nuts TD-T3564 (front), TD-1227- 
S-149 (rear), lock washers TD-1829-T-72, (front), TD-1229-X-700, 
(rear), and adjusting nuts TD-T3564 (front), TD-1227-S-149 
(rear), and pull off hub and drum assembly with wlieel bearings. 
(For more detailed information see pars. 15 and 22, TM 9-1705). 

((?) Remove shoe retracting Wheel cylinder clamp, 
spring. Special spring pliers. 

Clamp ends of wheel cylinder to hold pistons in place (fig. 39). 
Then remove spring LO-FC-2306 (front), LO-FC-2208 (rear), as 
shown in figure 40. 

{d) Remove guide pin washers. Screw driver. 

Hammer. 
Place screw driver against tang ends of C-washers LO-FC-4395 and 
drive them from pins LO-FC-4398 (short), LO-FC-4399 (long), by 
tapping screw driver. Then take off plain washers LO-FC--3911. 

(e) Remove brake shoe assem- Screw driver, 
blies. 

Remove anchor pin C-washers LO-FC-1165 (front), LO-FC-1166 
(rear) by forcing screw driver under end of washer and twisting. 

84 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 17 

Then remove spacer washers LO-FC-2719 (front), LO-FC-3719 
(rear), and slip off shoe assemblies LO-rD-2302 (front wheel for- 
ward), and LO-FD-2303 (front wheel rearward), LO-FD-2307 (rear 
wheel forward), and LO-FD-2308 (rear wheel rearward). Eemove 
guide pin washers LO-FC~3911 and guide pin springs LO-FC^753. 




3503A 



FiGDUE 80. — Clamping wheel brake cylinder. 



(2) Whtfel cylinder. —Tools : 
% 6-inch open-end wrench. 
%-inch open-end wrench. 



1%6 



Special spring pliers 
Cylinder clamp. 



inch open-end wrench, %-inch socket wrench 
and hub None. 



'/i 6-inch open-end wrench. 



(a) Remove wheel 
and drum assembly. 

Follow steps outlined in a(l) (a) and (b) above. 

(&) Disconnect inlet line to y^^ 
cylinder. %-inch open-end wrench. 

i%6~inch open-end wrench. 

Each front brake hose must first be disconnected at frame. Dis- 
connect inverted flared tube connector from hose frame fitting. Re- 
move frame fitting holding nut and turn hose assembly out of wheel 



85 



TM 9-1709 

17 



ORDNANCE MAINTENANCE 



cylinder inlet fitting. Disconnect eacli rear wheel cylinder line by 
tui-ning off flared tube connector from cylinder inlet fitting. 

(c) Kemove shoe retracting Special spring pliers, 
spring. Cylinder clamp. 

Clamp ends of wheel cylinder to hold pistons in place (fig. 39). 
Then remove spring as shown in figure 40. 

(d) Remove cylinders. %-inch socket wrench. 

Remove cap screws BCAXlEE and lock washers BECXIK and take 
out cylinder assembly LO-FC-1430 (front) , LO-FC-746 (rear) . 




Figure 40. — Removing brake shoe return spring. 



d. Disassembly of components. - 
Remove linings. 



-(1) Brake shoes (fig. 41). 

Punch. 
Hammer. 



Drive out rivets LO-FC-576 holding linings to shoes and remove 
linings LO-FD-2276 (front wheel forward), LO-FD-2277 (front 
wheel rearward), LO-FD-2281 (rear wheel forward), LO-FD-2282 
(rear wheel rearward). 

86 



TM: 9-1709 

chassis ai^d body foe scout cars m3a1 17 

(2) 'Wheel cylinder (fig. 42). 

(a) Remove working parts. None. 

Pull out yoke end connecting links LO-FC-671 (front), LO-FC- 
2200 (rear), rubber boots LO-FD-368 (front), LO-FC-726 (rear), 
pistons LO-FC-1311 (front), LO-FC-r23 (rear), cups LO-FC-857 
(front), LO-FC-725 (rear), and piston return spring LO-FC-860 
(front), LO-FC-724 (rear). 

(6) Remove fittings. Small pipe wrench. 

%-inch open-end wrench. 
%-inch open-end wrench. 
T^g-irich open-end wrench. 

Remove rear inlet fitting bolt LO-FC-673 (rear), bolt gasket 
LO-FC-603, inlet fitting LO-FC-672 (front), LO-FC-1079 (rear), 
LO-FC-602 and fitting gaskets LO-FC-603. Take out bleeder 
screw cap screw BCBX5A, lock washer BECXIG and bleeder screw 
LO-FD-372. 

e. Maintenance and adjustments. — (1) Inspect brake shoes for 
cracks and wearing of the anchor pin holes. If either are apparent, 
replace with new shoes. 

(2) Inspect adjusting cam friction springs and shoe retracting 
springs for breaks or evidence of permanent set and replace with new 
ones, if required. 

(3) Inspect anchor pins and their felt washers and replace any that 
show signs of wear. 

(4) If a minor adjustment of the brakes is required for any of the 
reasons listed in h above, it may be done as follows : 

(ffl) Without removing the wheels, raise the vehicle until the 
wheels are free of the ground. 

(6) Rotate the cam at the top of the front shoe until the lining is 
pressed firmly against the drum and the wheel is locked. 

(c) Then back off the adjustment slightly until the Avheel rotates 
freely without drag. 

(c?) Adjust all eight brake shoes in this manner. These cams are 
automatically locked in position by their friction springs. 

(5) If upon inspection, the brakes require relining for any of the 
reasons listed in 5 above, proceed as follows: 

{a) Remove the old linings by steps outlined in c(l)(a) to (t?), 
inclusive, and 6^(1) (a) above. 

(5) Set the new linings on the brake shoes and hold them in place 
with a suitable clamp (figs. 43 and 44). If 'the lining is not replaced 



87 



TM 9-1709 

17 



ORDNANCE MAINTENANCE 




A. 



r Lining, front 
) wheel 
I Lining, rear 
[ wheel 

I Shoe, front, 
assembly 
Shoe, rear 
assembly 

C. Link assembly 



r forward, LO-FD-2276. 
\ reverse, LO-Fr)-2277. 
/forward, LO-FD-2281, 
\ reverse, LO-FD-2282. 
J forward, LO-FD-2302. 
I reverse, LO-FD-2303, 
/forward, LO-FD-2307. 
\ reverse, LO-FD-2308. 
[front, LO-FC-671. 
1 rear, LO-FC-2200. 



E. 



RA P» 6241A 



^ ,. , ^, f front, LO-FC-1430. 

Cylinder assembly |^^^^.^ LO-FC-746. 

/front, LO-FC-2306. 
bprmg [vear, LO-FC-2208. 



F. Washer LO-FC-4395. 

G. Washer LO-FC-3911. 
r front, LO-FC-1165. 

"I rear, LO-FC-1166. 
[front, LO-FC-2719. 



H, Washer , 



I. Washer 



1 rear, LO-FC-3719. 



Figure 41. — Wheel brake disassembled. 



88 



TM 9-1709 

CHASSIS ADSTD BODY FOR SCOUT CARS M3A1 17 






a 
^ 


z 


-1^ 


p 


a 



89 



TM 9-1709 

17 ORDNANCE MAINTENANCE 

on all shoes, care must be taken to insure that the replacement lining 
is of the same type as the lining on the remainder of the shoes. 

(c) Rivet the linings to the shoes with the correct type of rivets. 
Never use aluminum rivets. 

{d) Countersink the rivet heads in the linings approximately two- 
thirds the thickness of the linings. 

(e) Chamfer the ends of the linings back about % inch from the 
top and bottom, and remove high spots and burs around the rivet holes, 
with a grinding tool or a fine file (fig. 45). Do not use emery paper. 

(/) Reinstall brake shoe assemblies as explained in g below. 

(6) After the brakes have been relined or the brake drums resur- 



RA I'D 6374 ^^ 

Figure 43. — Holding brake lining while riveting to shoe. 

faced, a major adjustment of the shoes is necessary and should be 
done as follows : 

(a) With the wheels and drums in place and the vehicle raised, 
remove the inspection hole covers in the brake drums. 

(5) Insert a thickness gage through the inspection hole between 
the lining and drum (fig. 46) . 

(c) Loosen the holding bolt at the rear of the backing plate, and 
turn the eccentric anchor pins at the "heel" or lower end of the brake 
shoe. At a distance of 1 inch from the end of the lining near this pin, 
the clearance between lining and drum should be 0.005 inch. 

{d) Tighten the holding nut and recheck clearance. 

(e) Turn the wheel and drum assembly until the inspection hole 
in the drum is at the "toe" or upper end of the shoe. 

90 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS MSAl 17 



RA m 63T4A 




RA PD 6371 



FlGDBB 45. — Beveling edges of brake lining. 

91 



TM 9-1709 

17 



ORDNANCE MAINTENANCE 



(/) Insei^t a gage between the lining and drum 1 inch from the end 
of the lining and turn the adjusting cam belt until the lining has a 
clearance of 0.010 inch (fig. 47) . 

{g) Remove the gage and replace the inspection hole cover. 

(A) Check the pedal travel before and after these adjustments and 
tighten holding bolts. Repeat these operations on each shoe in each 
drum. 




Figure 46. — Wheel brake shoe toe adjustment. 

(7) Inspect brake drums for scratches and scoring. Resurface, if 
necessary, by turning on drum lathe. 

(8) After a wheel cylinder has been disassembled, wash the woi-k- 
ing parts hi alcohol and inspect for the following : 

(a) If any mineral oil has found its way into the system, the rub- 
ber cups will be enlarged and very soft. If this condition is ap- 
parent, replace the cups. 



92 



TM 9-1709 

CHASSirS ANV BODY FOR SCOUT CARS M3A1 17 

(i) Cylinder walls must be smooth (not pitted or scratched) . The 
walls may be renewed by honing. If this is done, use a "no-go" gage 
to determine whether the diameter has been enlarged to a point where 
this casting, cannot be used. 

(c) Pistons must be free from burs. If any burs are apparent, 
remove them with a fine file. 

(d) Occasionally, wheel bearing grease seals become worn and 
allow grease to leak through into the brake drum and come in con- 
tact with the cylinder rubber boots. When this occurs, the boots be- 
come soft and enlarged, and do not protect the cylinder from foreign 




IfiGCEE 47. — Wheel brake shoe heel adjustment. 

matter. If this condition is apparent, replace boots and grease 
I'etainers. 

(e) Check tlie return spring for peimanent set and if any is appar- 
ent, re]3lace with a new spring. 

Note. — Never wash cylinder or parts in gasoline, iterosene, oil, or solvent, 
dry-cleaning. 

93 



TM 9-1709 

17 OEDKANCB MAINTENANCE 

(9) Service data. 
Wheel cylinders: 

Piston clearance, front 0.001 to 0.005 in. 

Piston clearance, rear 0.001 to 0.005 in. 

Front and rear shoe adjustment : 

Cam (top of shoe) 0.010 in. 

Eccentric (bottom of shoe) 0.005 in. 

Brake return springs : 

Front cylinder piston : 

Free length 2% in. 

Pressure at 1% inch 1 to li41b. 

Kear cylinder piston : 

Free length 3% in. 

Pressure at 2 inches li/^to21b. 

Shoe return springs: 

Free length T^gin. 

Pull at 81/4 inches 75 to 85 lb. 

Brake drum : 

Regrinding limints 0.030 in. 

/. Reassembly of eoniponents. — (1) Brake shoes. 

Replace or renew linings. Clamp, grinder or file, and rivet 

punch. 

Follow steps outlined in e(5) (&) to (e), inclusive, above. 
(2) Wheel cylinder. 

Replace working parts. Clamp. 

Dip parts in brake fluid and then place piston spring in center of 
cylinder and install rubber cups on each end of spring with their 
flat faces out. Insert pistons into each end of cylinder, flat face 
first so that they butt against flat face of cups. Slip rubber boots 
over each end of cylinder and insert connecting links through holes 
in boots until they seat into pistons. Hold parts in place by clamp- 
ing ends of cylinder. 

g. Installation of assembly. — (1) Wheel cylinder (fig. 41). — Tools: 

%-inch socket wrench. n/ig-inch open-end wrench. 

%-inch socket wrench. Wheel bearing nut wrench. 

Special spring pliers. Hammer. 

yx 6-inch open-end wrench. Wheel stud nut wrench. 

%-inch open-end wrench. Screw driver. 

1%6-inch open-end wrench. Lockheed filler jar and nozzle. 



94 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 17 

(«) Replace cylinder. %-inch socket wrench. 

Set cylinder links in shoe recesses and attach cylinder to brake 
backing plate with cap screws and lock washers. 

(i) Replace shoe retracting Special spring pliers, 
spring. 

Clip one end of spring onto upper guide pin slot of forward shoe, 
stretch spring with pliers, and clip other end of spring onto upper 
guide pin slot of reverse shoe (fig. 39) . 

(o) Attach inlet line to cylin- %e -inch open-end wrench, 
der inlet fitting. %-inch open-end wrench. 

i%e-inch open-end wrench. 

Rear wheel cylinder lines are connected by screwing flared tube 
connector onto cylinder inlet fitting. Each front brake hose is con- 
nected by screwing one end into cylinder inlet fitting; then attach 
opposite end fitting to frame and reconnect line to hose fitting with 
inverted flared tube connector. 

(d) Replace hub and drum %-inch socket wrench, 
assembly. , - % e-inch open-end wrench. 

Wheel bearing nut wrench. 
Hammer. 

Replace hub and drum assembly and outer wheel bearing assembly 
on axle. Then fasten assembly in position with wheel bearing ad- 
justing nut, lock washer and locking nut, and adjust for correct bear- 
ing pressure. Replace drive flange assembly on front axle (or axle 
shaft assembly in rear axle) and fasten with lock washers and nuts. 
(For more detailed information see pars. 17 and 24, TM 9-1705.) 

(e) Replace wheel and tire as- Wheel stud nut wrench, 
sembly. 

Set assembly onto wheel studs and replace stud nuts. Lower vehicle 
to floor, remove jack and tighten nuts. 

(/) Bleed lines. Screw driver. 

Lockheed filler jar and nozzle. 
yi e-inch open-end wrench. 
Follow steps outlined in paragraph lQd{2){a) to (k), inclusive. 
(2) Brake shoes. 

(a) Replace shoes. Light hammer. 

Set felt seals, retainers, and washers onto anchor pins and guide 
pin springs and washers onto guide pins. Then set shoes onto anchor 
pins and guide pins and lock them in position by replacing anchor 

95 



TM 9-1709 

17-18 OEtDTTANCB IVnArNTENANCB 

pin spacer washers and C-washers and guide pin plain washers and 
C-washers. 

(&) Eeplace shoe retracting 
spring. 

See (1)(&) above. 

(c) Replace hub and drum as- 
sembly. 

See (1) (d) above. 

{d) Eeplace wheel and tire as- 
sembly. 

See (1) (e) above. 

18. Drive shaft brake (figs. 48 and 49). — a. Description. — The 
drive shaft brake is a two-shoe, ventilated disk type. It operates 
on disks mounted on the companion flange of the propeller shaft at 
the rear of the transfer case. 

(1) Construction (fig. 50). — («) The polished steel brake disk as- 
sembly is mounted to the rear propeller shaft companion flange at the 
rear of the transfer case and is held in place by bolts, nuts, and cotter 
pins. The brake anchor bracket straddles the disk assembly at its 
upper left side and is bolted to the frame bracket by three cap screws 
and lock washers. The upper ends of the front and rear brake shoe 
lever arms are yokes which fit over the lower extremities of the anchor 
bracket and are held in place by anchor pins which pass through the 
yoke eyes and companion holes drilled through the bracket. The 
anchor pins are grooved at the center so that the lock screws, threaded 
into the anchor bracket at right angles to the pins, fit into these grooves 
and thereby lock the pins in place. The lever arms pivot on these pins 
and lubrication is obtained through fittings which are threaded into 
the anchor bracket just below the locking screws. 

{b) The brake shoes straddle the lever arms and are held in place by 
pins which pass through the shoes and arms. The shoes swivel on these 
pins and are lubricated by grease fittings threaded into the ends of the 
pins. The pins are held in place by means of retainers which fit into 
grooves cut close to the outside ends of the pins. The retainers are 
bolted to the brake shoes by cap screws and lock washers. The brake 
linings are riveted to the shoes and are held parallel to the brake disk 
by a connecting spring at the bottom of the shoes and adjusting set- 
screws at the top. 

(c) The operating lever tie rod is threaded at one end and has a 
flattened eye at the other. The eye sets into the upper clevis of the 
operating lever and is held by a clevis pin and cotter pin. The rod 



96 



TM 9-1709 

CHASSIS AND BODY FOE SCOUT OARS M3A1 18 




C. Flange WI-94918. 

D. Disk assembly TRU-C-20S-2A. 



A. Fitting CLDX5M. 

fBolt WI-A6988X. 
B.J Nut BBBXID. 

[Washer, lock, BECXIL. 

Figure 48. — Drive shaft brake assembly, installed — bottom view 



477229° — 42 7 



97 



TM 9-1709 
18 



ORDNANCE MAINTENANCE 




D 



RA PD azi. ■■• 

{Support WI-347374. 
Screw, cap, BCBXICA. 
Nut BBBXIC. 
Washer, lock, BECXIK. 
I Clamp OM-C-8. 
Screw, cap, BCBXICD. 
Nut BBBXIC. 
Washer, lock BECXIK. 
H. Muffler assembly WI-H53739. 

Figure 49. — Drive shaft brake assembly, installed — top view. 



A. Fitting CLDX5A. 

B. Lining TEU-C-4. 

C. Bracket TRU-C-5ol. 
(•Screw, cap, BCAXIEB. 
\ Washer, lock, BECXIM. 

E. Bracket WI-347309. 



98 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 18 




' ■ 



A — 



, 



f 







— D 



s^pz; 




A. Lever assembly WI-347371. 

B. Rod assembly WI-347363. 



RA PD 7409A 

C. Brake, w/bracket, assembly TEU-20-5- 



00310. 
D. Pin BFITXIF. 



Figure 50. — Drive shaft brake assembly. 

99 



TM 9-1709 

18 OKIDNANCE MAINTENANCE 

then passes through the slotted hole in the front brake shoe lever arm 
and through the rear lever arm and is held by a spherical nut and a 
lock nut. The brake lever arm release spring, with a thrust washer at 
each end, is carried by the tie rod between the front and rear brake 
lever arms. 

{d) The clevis at the bottom of the operating lever straddles the tang 
at the bottom of the front brake lever arm and the lever is attached 
to the arm at this point by a clevis pin and cotter pin. The top of the 
operating lever sets into the brake pull rod yoke end and is held by 
a clevis pin and cotter pin. The opposite end of the pull rod is 
threaded into the brake lever block and is held fast by a lock nut. The 
lever block has a rod end which passes through the bottom of the 
lever and the slot in the quadrant and is held to the lever by a washer 
and cotter pin. 

(e) The brake lever has a forked end at the bottom which straddles 
the quadrant and is bolted to it by means of a cap screw, castle nut, 
and cotter pin (fig. 51). The quadrant sits on two studs which are 
threaded into the left side of the transmission housing and are held 
by means of two nuts and lock washers. The bottom of the quadrant 
has teeth cut into it to mate with the pawl, which sits into the clevis 
at the bottom of the brake lever and is held by a clevis pin. The pawl 
is actuated by the pawl rod which is attached to it by a cotter pin. 
The pawl rod then passes up through the brake lever casting and is 
held by a spring, a button, and pin at the top of the lever. 

(2) Functioning. — ^When the brake lever is in its released position, 
the lever arm release spring spreads the lever arms and holds the shoes 
away from the brake disks. When any braking is desired, the brake 
lever is pulled back at the top and the bottom moves forward. The 
pawl moves forward with the bottom of the lever arm, slipping over 
the quadrant teeth until the desired amount of breaking is reached, 
at which time the brake lever is released and the pawl engages with 
the quadrant teeth and holds the brake lever in the desired position. 
The forward "movement of the bottom of the brake lever carries with it 
the lever block and the pull rod which is held in the block. The pull 
rod pulls the top of the operating lever forward. This causes the 
lever to pivot at the point where it is attached to the front brake shoe 
lever arm and at the same time it pushes the arm toward the rear and 
pulls the operating lever tie rod forward against the resistance of the 
release spring. The rearward motion of the bottom of the front lever 
arm makes the arm pivot on the pin which holds it to the anchor 
bracket and it brings the front brake shoe in contact with the front 



100 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 18 




I Stud WI-347369. 
Washer, lock, BECXIM. 
Nut BBBXIC. 
Washer, lock, BECXIK. 
B. Lever assembly WI-347371. 

Figure 51. — Drive shaft brake hand lever, installed. 



RA PD 9838 



101 



TM 9-1709 
18 



OmDNANCE MAINTENANCE 



brake disk. At the same time, the forward pull of the tie rod causes 
the rear brake lever arm to pivot on its holding pin and bring the rear 
brake shoe in contact with the rear brake disk. In this manner, both 
brake shoes contact the disks at the same time and with an equal 
amount of pressure. To release the brake shoes, depress the pawl rod 
button at the top of the brake lever and at the same time apply a slight 
backward pressure on the lever to facilitate the pawl dropping away 
from the sector teeth. Push the top of the lever forward and this will 
release the mechanism back to the release spring. 
(3) Specifications. 



Make 


Model 


Type 


Manufacturer's No. 


Ordnance 

No. 


White 
No. 


American Cable 
Co. 


20-S-00310 


Two-shoe _ 


TRU-20-S-00310 


D33798 


311908 



Disk diameter inches 12 

Hand brake shoe : 

Size do 7. 85by2 

Lining area (total for both sides) 

square inches 411/^ 

&. Trouble shooting. 

Symptom and proiaMe cause Pro'baHe remedy 

(1) Brake will not hold. 

Shoes improperly mounted. Check shoes and connections and 

readjust. 
Linings worn. Replace with new linings. 

Shoes out of adjustment. Eeadjust. 

(2) Brake drags. 

Kelease spring broken. Replace with new spring. 

Release spring taken per- Replace with new spring. 

manent set. 
Operating lever sticks. Lubricate pivot pin. 

(3) Brake lever will not hold in 

"on" position. 
Worn or broken pawl tooth. Replace pawl. 
Worn or broken quadrant Replace quadrant. 

teeth. 



102 



TM 9-1709 

CHASSIS AND BODY FOB SCOUT OARS M3A1 18 

c. Removal of assembly.-^ (1) Disk brake. — Tools: 

Pliers. l^^-inch open-end wrench. 

%-inch open-end wrench. %-inch open-end wrench. 

%-inch open-end wrench. %-inch box wrench. 
i%g-inch open-end wrench. 

(a) Disconnect pull rod at oper- Pliers, 
ating lever. 

Pull out cotter pin BFAXlDG from rod end pin BFFXIF and 
remove rod end pin. 

(b) Remove brake assembly Pliers. 

without disk. %-inch open-end wrench. 

%-inch open-end wrench. 
^%6"inch open-end wrench. 
1 %-inch open-end wrench. 

Kemove shoe springs TEU-C-514. Loosen shoe adjusting set screws 
TRU-C-620-1 and tie rod lock nut and adjusting nut. Then remove 
three cap screws BCAXIEE and lock washers BECXIM holding 
anchor bracket to frame bracket and lower brake assembly (fig. 50). 

(o) Remove disk assembly. %-inch box wrench. 

%-inch open-end wrench. 

Remove four nuts BBBXlD, lock washers BECXIL and bolts 
WI-A6998X holding rear propeller shaft flange and brake disk to 
companion flange at rear of transfer case. Lower propeller shaft 
and disk assembly to floor. 

(2) Brake lever. 

(a) Disconnect pull rod at 
operating lever. 

See (1) (a) above. 

(b) Remove lever assembly with ^g-inch open-end wrench, 
pull rod. 

Remove two nuts BBBXlC and lock washers BECXIK holding 
sector CE-1577 to transmission housing and lower assembly to floor 
(fig. 50). 

d. Disassembly of comf orients. — (1) Dish brake (fig. 52). — Tools: 

Pliers. %-inch socket wrench. 

1%-inch open-end wrench. Pivot punch. 

%-inch open-end wrench. Hammer. 
%-inch open-end wrench. 

103 



TM 9-1709 

18 



OEiDI^ANCE MAINTEWANCB 




104 



TM 9-1709 

CHASMS AND BODT FOR SCOUT CARS M3A1 18 



^' y, < 

• ■? H S ft «' 1 

fe « P^M tJ W « g !&fe Z Z 

hi J S Z d P-' ff si a; H b >' 



^ s ^ s V 4 f 4 ^ ^ ;? I o 

S 8 t: g » ^ g ^ g E^ ^ g « 

•5.S55B£"5S35Sc = 
ju^3 ^ « ^£^M ^ S E- 

-!< ca d D 65 fed S ^ w 



105 



TM 9-1709 

18 ORDNANCE MAINTENANCE 

(a) Remove brake assembly from 
vehicle. 

Follow steps outlined in c(l) (a), (h), and (c) above. 

(b) Remove operating lever and Pliers. 

tie rod. li^-inch open-end wrench. 

Remove tie rod lock nut BBBXIE and spherical nut TRU-C483-A 
Then pull out cotter pins BFAXIDF and clevis pins TRU-RA-12-6 
holding operating lever TRU-C-552 to front brake shoe lever arm. 
Remove operating lever, tie rod TRU-C-479, release spring TRU-C- 
513, and washers BEBXIM. 

(c) Remove brake shoe assem- i/2-i^ch socket wrench, 
blies. 

Remove brake shoe pin retainer cap screws BCAX3AB, lock washers 
BECXIH, and pin retainers TRU-C-542. Then pull out brake shoe 
pins TRU-C-509 and remove shoe assemblies. 

(d) Disconnect brake shoe lever %-inch open-end wrench, 
arms from anchor bracket. %-inch open -end wrench. 

Loosen setscrew lock nuts BBAXIB and turn adjusting screws 
TRU-C-512-2 out of anchor bracket TRU-C-551 until they are free 
of grooves in anchor pins. Pull out anchor pins TRU-C-507 and 
remove lever arms TRU-C-545 (front), TRU-C-543 (rear). 

(e) Remove linings from brake Pivot punch, 
shoes. Hammer. 

Punch out rivets BMCXl holding linings TRU-C-4 to shoes TRU- 
C-505 and remove linings. 
(2) Brake lever. — Tools: 

%-inch open-end wrench. Drift. 
%6"irich open-end wrench. Hammer. 
Pliers. %6-™ch socket wrench. 

File. Punch. 

(«) Remove brake lever assem- 
bly from vehicle. 

Follow steps outlined in c(2) (a) and (5) above. 

(&) Remove yoke end pull rod. %-inch open-end wrench. 

Mark position of lock nut BBDX2B on pull rod to facilitate reas^ 
sembly. Then loosen nut and turn pull rod WI-347363 out of lever 
block WI-347370 (fig. 53). 



106 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 18 

(c) Remove lever block. Pliers. 

Pull out lever block cotter pin BFAXlCG and remove washer 
BEBXIK and lever block (fig. 53) . 

(d) Remove pawl. Pliers. 

File. 

Drift. 

Hammer. 

File end of clevis pin TRU-RA-12-6 and drive pin out of brake 
lever clevis and pawl CE-1543. Then pull out pawl rod cotter pin 
BFAXIBF and remove pawl from pawl rod. 

(e) Remove sector. %6"iiich open-end wrench. 

%6-™ch socket wrench. 
Pliers. 

Pull out castellated nut cotter pin BFAXlCG and remove nut 
BBFXIC and bolt WI-A3062X, holding sector to lever. Slip sector 
CE-1577 out of lever :fork. 

(/) Remove pawl rod. Punch. 

Hammer. 

Drive out pin CE-1625, holding pawl rod button CE-1622 in lever 
handle, and remove button and spring WI-A35987X. Then pull pawl 
rod out of lever. 

e. Maintenance and adjustments. — (1) Brake shoes normally must 
be parallel to and not touch the disk when the brake is in the released 
position. If they are found to be out of parallel, adjust by turning 
the top adjusting setscrews at the front and rear of the anchor bracket. 

(2) Inspect linings and if they are worn close to the rivets re- 
place with new linings of the same make, as follows : 

(a) Remove old linings from shoes by following steps outlined 
in d{l) (a), (b), (c), and (e) above. 

(i) Set the new linings on the brake shoes and hold them in place 
with a suitable clamp. . 

(c) Rivet the linings to the shoes with the correct type of rivets. 
Never use aluminum rivets. 

(d) Remove the high spots and burs around the rivet holes with 
a fine file. Do not use emery paper. 

(e) Replace the brake shoes as explained in / below. 

(3) When the linings wear so that the brake will not hold, or after 
relining the shoes, adjust as follows : 

(a) Release the hand brake lever fully and disconnect the pull 
rod at the operating lever by removing the cotter pin and clevis pin. 

107 



TM 9-1709 
18 



OR'DWANCE MA-tNTEWlANCE 




<j m o 



108 



TM 9-1709 

CHASSIS AND BODY POR SOOXJT C5ARS M3A1 18 

(6) Tighten operating lever tie rod spherical adjusting nut so 
that the lever arm release spring on the tie rod will draw the oper- 
ating lever firmly against the front brake lever arm. 

(e) Insert a %2-inch shim or feeler gage between the front shoe 
lining and disk (fig. 54). 

[d) Adjust hand lever pull rod to maintain this clearance and re- 
connect pull rod to operating lever by replacing clevis pin and cot- 
ter pin. 

(e) Adjust rear shoe for the same clearance with the disk and 




RA P0 3544, 



FiGuuK 54. — Drive shaft bnike front slioe lid.justnienl. 



tighten locking nut on rear end of tie rod to keep this spacing (fig. 
55). 

(/) Make sure that the spring connecting the lower ends of the 
broke shoes, is in place and adjust the top screws at the front and 
rear of the anchor bracket to make shoes and linings parallel to disk. 

(g) Remove shims. 

(4) Inspect all clevis and anchor pins and replace any that are 
badly worn or damaged. 

(6) Check lever arm release spring, shoe connecting spring, and 



109 



TM 9-1709 

18 OEDNANCB MAINTENANCE 

pawl rod spring for breaks or signs of permanent set and replace 
if necessary. 

(6) Inspect pawl and quadrant for worn or broken teeth and 
replace with new parts if required. 

(7) Service data. 
Brake adjustment: 

Clearance, linings to disk %2 in- 

Brake release spring: 

Free length 4% in. 

Pressure at 4%6 inches 60 lb. 




Ki'-uKK 5o. --Drive shaft brake rear shoe aUjufclUiuiil. 

/. Reassembly of comfonents. — (1) Dish 'brake (fig. 52). — Tools: 

%-inch open-end wrench. li/^-inch open-end wrench. 

%-inch open-end wrench. 1/2-inch socket wrench. 

%-inch open-end wrench. Pliers. 

(a) Fasten linings to shoes. 

Follow steps outlined in e(2) (6), (c), and {d) above. 

(J) Attach brake shoe lever %-inch open-end wrench, 
arms to anchor bracket. %-inch open-end wrench. 

110 



TM 9-1709 

CHASSIS AND BODY FOB SOOUT OARS M3A1 18 

Hold lever arms in position and replace anchor pins. Turn in set- 
screws until anchor pins are locked in place and tighten setscrew 
lock nuts. 

(c) Attach brake shoe assem- i/2-iiich socket wrench, 
blies to lever arms. 

Straddle lever arms with brake shoes and replace brake shoe pins. 
Then lock pins in place with pin retainers, retainer holding cap 
screws, and lock washers. 

{d) Attach tie rod to operating Pliers, 
lever. 

Slip tie rod eye into operating lever clevis and replace clevis pin 
and cotter pin. 

(e) Keplace operating lever %-inch open-end wrench, 
w/tie rod. li^-inch open-end wrench. 

Pliers. 

Slip tie rod through front lever arm and install release spring and 
washers on rod. Then push rod through rear lever arm and start 
spherical nut and lock nut on threaded section of rod. Attach lower 
part of operating lever clevis to front lever arm by replacing clevis pin 
and cotter pin. 

(2) Brake lever. — Tools : 

Hammer. %-inch open-end wrench. 

Fine file. %6"iiich socket wrench. 

%6-™ch open-end wrench. Pliers, 
(a) Replace pawl rod. Hammer. 

Fine file. 

Insert pawl rod into lever handle, install spring and button, and 
stake assembly with button pin. File end of pin flush with handle. 

(&) Replace sector. %e-inch open-end wrench. 

%6"iiich socket wrench. 
Pliers. 

Slip sector into fork at bottom of lever and fasten in position with 
cap screw, castellated nut, and cotter pin. 

(c) Replace pawl. Pliers. 

Hammer. 

Hook pawl on to bottom of pawl rod and fasten it into lever fork by 
inserting pin and peening over its inner end. 

{d) Replace lever block. Pliers. 

Ill 



TM 9-1709 

18 ORDNANCE MAINTENANCE 

Insert lever block rod end through lever fork and slot in sector and 
replace holding washer and cotter pin. 

(e) Replace yoke end pull rod. %-inch open-end wrench. 

Turn threaded end of pull rod into lever block until mark made 
at disassembly is reached. Then lock rod in this position with its 
lock nut. 

g. Installation of assembly. — (1) Disk hrake (figs. 48 and 49). — 

Tools : 

%-inch open-end wrench. fi/j^-inch open-end wrench. 
%-inch open-end wrench. %-inch box wrench. 
%-inch open-end wrench. Pliers. 
iS/jg-inch open-end wrench. i/^2"™ch shims. 
{a) Attach anchor bracket 34-inch open-end wrench, 
w/brake assembly to frame 
bracket. 

Hold anchor bracket assembly in position and replace cap screws 
and lock washers, holding anchor bracket to frame bracket. 
(6) Replace disk assembly. %-inch box wrench. 

%-inch open-end wrench. 

Slip disk assembly between brake shoes and hold it in its normal 
running position. Then bring propeller shaft into position and in- 
sert bolts through transfer case companion flange, disk spider, and 
propeller shaft flange. Fasten assembly with lock washers and nuts. 

(c) Replace brake shoe spring. Pliers. 

Hook one end of spring on to bottom of front shoe, stretch spring, 
and hook opposite end on to bottom of rear shoe. 

{d) Adjust brake shoes. %-inch open-end wrench. 

%-inch open-end wrench. 
i%g-inch open-end wrench. 
1%-inch open-end wrench. 
% 2 -inch shims. 
Pliers. 

Follow steps outlined in e(3) (J) to (c?), inclusive, above. 

(2) Brake lever. 

(a) Attach lever assembly to %e-inch open-end wrench, 
transmission housing. 

Push lever up through floor plate and set sector onto studs in side of 
transmission housing. Fasten assembly with lock washers and stud 
nuts. 

112 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 18-19 

(h) Connect i^uU rod yoke end Pliers, 
to top of operating lever. 

Insert clevis pin through yoke end and lever and lock clevis pin in 
place with cotter pin. Check brake adjustment. 

Section VI 
COOLING SYSTEM 

Paragraph 

Description 19 

Trouble shooting 20 

Radiator 21 

Water puinp and fan assembly 22 

19. Description. — The water-cooling system (fig. 56) consists of 
the engine water jacket, water outlet fitting, radiator, centrifugal 
water pump, connecting pipes and hoses and shroud inclosed fan. 
The radiator is located in front of the engine and is connected to 
the engine water outlet and the water pump inlet by means of brass 
pipes with short rubber hose connections at both ends. The water 
pump is bolted on the left front side of the engine block and is con- 
nected to the engine water inlet by a short rubber hose. The pump 
is gear driven from the camshaft gear by means of the engine idler 
gear. The fan is bolted to the front of the pulley hub and the 
pulley is mounted on roller bearings on a stationary shaft. The 
shaft is carried by an adjustable bracket mounted on the engine 
timing gear cover. The shaft assembly can be adjusted vertically 
by means of the bracket handwheel and screw assembly so that the 
driving V-belts can be kept at the proper tension at all times. The sys- 
tem may be drained by removing the water pump discharge plug 
and opening drain cocks located in radiator outlet pipe and in the 
left rear side of the .engine block. Vents sealed by plugs in the 
engine water outlet fitting and the water pump inlet fitting are 
provided for installing a heater. 

a. Functioning. — The pump circulates cooled water from the radi- 
ator throughout the channels in water jacket and cylinder head. The 
warmer liquid which rises to the top of the water jacket is forced 
through the radiator inlet into the upper radiator tank, flows down 
the radiator tubes for cooling, and is redrawn from the lower tank 
into the pump to repeat the cycle. Air, rushing through the radiator 
fins and around the tubes, cools the liquid as it descends through 



477229°— 42- 



113 



TM 9-1709 

19-20 OBiDNANCE MAINTENANCE 

the tubes and is then blown back over the engine by the fan to help 
keep the engine cool. 
h. Specifications. 

Cooling capacity 19 quarts. 

Water pump : 

Type Impeller. 

Make Hercules. 

Model 40170-CS. 

Location Left front side of cylinder block. 

Drive Double V-belt. 

Impeller location Pump body. 

Bearings Bushings. 

Fan: 

Make Schwetzer-Cummins Co. 

Number A-105005. 

■ Diameter 19 inches. 

Number of blades 6. 

Fan belts : 

Make Gates. 

Type V. 

Width 34 inch. 

Length 62% inches. 

Radiator core : 

Make Modine. 

Number AD3683. 

Type Fin and tube. 

Frontal area 555 square inches. 

Thickness 3% inches. 

20. Trouble shooting. 

Synipton and proiaUe cause Probable remedy 

a. Overheating. 

Radiator dirty inside or out. Clean radiator thoroughly. 

Dirty water. Drain and refill with clean water. 

Engine timing wrong. Time engine correctly. 

Fan belts slipping on fan Take up belt slack. 

pulley. 

Thermostat not functioning Replace with new one. 

correctly. 

Restriction in system. Clean system to remove restriction. 

Air being drawn into system. Tighten hose connections. 



114 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 20-21 



h- Loss of cooling liquid : 

Loose hose connections. 
Damaged hose connections. 
Leaking water pump. 
Leaks in radiator core. 
Loose or open drain cocks. 



Tighten all connections. 
Replace damaged hose. 
Replace pump. 

Remove core and repair leaks. 
Check and tighten. 



21. Eadiator (fig. 57). — a. Description. — The radiator is of the 
two-tank, fin and tube type. 

(1) G onstruotion. — The radiator consists of two brass tanks with 
the core set in between the tanks and the tubes brazed into each tank 
at their ends. The assembly is' reinforced by an angle framework 
around the outside. The inlet fitting is brazed into the right-hand 
side of the upper tank and the filler neck to the left side. The outlet 
fitting is brazed into the left side of the lower tank. The filler neck 
has an overflow pipe welded into it at the top. The shroud is held 
to the radiator frame by screws. The radiator mounting bolts are 
welded into the saddle, which in turn is spot-welded to the bottom 
reinforcing bar. The studs for the side bracing rods are welded into 
the reinforcing bar at each side of the radiator. 

(2) Functioning. — The system is filled with fluid through the filler 
neck. The liquid comes into the upper tank through the inlet fitting, 
goes down through the tubes to the lower tank and out through the 
outlet fitting. Air rushing through the fins and around the tubes 
cools the liquid as it runs down through the tubes. 

(3) Specifications. 



Make 


Type 


Manufacturer's No. 


Ordnance No. 


White No. 


Modine 


Fin and tube 


AD-3583 


D38075 


361046 





5. Removal of assembly (fig. 58). 

Pliers. 

Large pail. 

%6-inch open end-wrench. 

1% 6-inch open-end wrench. 



-Tools : 

Screw driver. 
%-inch socket wrench. 
%-jnch socket wrench. 
Hoist. 



(1) 



%-inch open-end wrench. 
Drain radiator. 



Open drain cock WH-140 in 



Pliers. 
Large pail, 
radiator lower 



WI-326396 and drain liquid into pail or on ground. 



tube assembly 



115 



TM 9-1709 
21 



ORDNANCE MAINTENANCE 




116 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 21 




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117 



TM 9-1709 
21 



ORiD]SnA]SPCE MAINTENANCE 




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TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 21 




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119 



TM 9-1709 

21 OffiDNANiCE MAJNTENAISICE 

(2) Kemove hood. %Q-mch open-end wrench. 

Eemove six screws DS-H-12083, nuts BBSX4AE and lock wash- 
ers BECXIE holding hood top plate DS-PA-2752-13 to top of 
shutter frame and cowl. (This procedure is for lot 1 cars. For lot 2 
cars, remove three elastic stay nuts and bolts at rear of center 
panel of hood.) Remove nut and bolt on inside of shutter frame, 
near top, on both sides of frame. Hood can be lifted leaving top of 
lower frame on hood. Lift off hood with hoist and rope, or three men 
can slide it over front of car. 

(3) Remove fan assembly (fig. li/m-inch open-end wrench. 
59). %-inch open-end wrench. 

Loosen fan belt by turning spindle jam nut and adjusting screw 
lock nut. Remove two screws and washers holding fan bracket. Re- 
move fan belts. Remove fan assembly with bracket. 

(4) Disconnect upper and low- Screw driver, 
er radiator hose connections. 

Unscrew hose clamp bolts BAOXlCD, loosen clamps WI-A42751, 
and pull hoses AQRXl from inlet and outlet fittings. 

(5) Disconnect bottom of radi- %-inch socket wrench, 
ator from frame. Pliers. 

Remove radiator mounting stud cotter pins BFAXICG and 
castle nuts BBFXlE and take off washers BEBXlCM, springs 
WI-A8596X and spring pads WI-376208. 

(6) Disconnect stay rods at %-inch socket wrench, 
each side of radiator. 

Remove nuts BBBX2A and lock washers BECXIN holding stay 
rod WI-315138 (left) WI-315137 (right), to frame and pull stays 
free of studs. 

(7) Remove radiator assembly. Hoist. 

Lift radiator assembly MO-AD-3583 out of frame by pulling up 
and slightly to front so that shroud clears fan (fig. 60) . 
0. Disassembly. — Tools : 

% 6'iiich open-end wrench. Blow torch. 
Screw driver. 
(1) Remove radiator assembly. 



120 



TBI 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 21 






121 



TM 9-1709 

•21 OBDWANCB MAINTENANCE 

Follow steps outlined in 6(1) to (7), inclusive, above. 

(2) Eemove shroud. s/ig-inch open-end wrench. 

Screw driver. 

Remove 18 nuts BBKX26, lock washers BECXIE, and screws 
BCNX2AG holding shroud WI-316765 (left), WI-316763 (right) 
(fig. 61). 

(3) Eemove filler neck. Blow torch. 

Heat section of filler neck MO-A-9062, at point of attachment, until 
solder runs, then pull off neck. 

(4) Remove inlet and outlet Blow torch, 
fittings. 

Follow procedure used in (3) above. 

d. Maintenance and repairs. — (1) Check the inlet and outlet fit- 
tings and the filler neck for damage or breaking away at the points 
where they are attached to tanks. If any is apparent, proceed as 
follows : 

(a) Remove fittings as explained in c above. 

(&) If the fittings are damaged, replace with new ones. Otherwise, 
remove solder from old fitting. 

(c) Solder filler neck and inlet and outlet fittings to tanks. 

(2) At least every 20,000 miles, remove radiator core and clean it 
inside and out with a cleaning solution. At the same time, examine 
core for leaks and bent tubes. Repair if necessary. 

{a) The leaks can usually be repaired by soldering. 

(6) Bent tubes can be straightened by pushing a long steel bar 
through them. This will also clean them. All tubes should be sub- 
jected to this process. 

(c) If the radiator core requires painting, spray with special radi- 
ator paint. Do not use paint mixed with oil, as this type will form an 
insulation on the core and prevent dissipation of heat. 

(3) Inspect mounting studs. If they are bent or damaged, replace 
with new studs in the following manner : 

(a) Cut off old studs close to saddle. 

(6) Drill remainder of studs out of saddle. 

(c) Insert new studs and weld them to top of saddle. 

(4) Check mounting springs. If they have taken a permanent set 
or are damaged, replace them. 

(5) Inspect mounting pads and replace with new ones, if necessary. 

(6) Service data. 



122 



TM 9-1709 

CHASSIS AND BODY FOR SOOXJT OARS M3A1 31 




123 



TM 9-1709 

21 OEiDjNTANiCE mmntegstance 

Stay rod studs (each side of radiator) : 

Size 1/2-20 SAE threads (1 inch x 1% inches.) 

Bottom mounting studs: 

Size 1/2-20 SAE threads (1 inch x 2% inches.) 

(7) Check construction of radiator overflow pipe. 

(a) All scout cars M3A1 are equipped with radiators in which the 
overflow tube begins just below the top of the radiator filler neck cap 
and passes downward through the bottom of the filler neck and along 
the left side of the radiator. On these vehicles the top opening of 
the overflow pipe will be restricted in accordance with the following 
instructions in order to prevent excessive loss of cooling fluid. 

1. Remove radiator cap and insert a strip of shim stock 14 g by 

%6 by 3 inches into top opening of overflow pipe. 

2. Pinch sides of tube against shim stock. 

3. Pull shim stock out of overflow tube and replace radiator 

filler cap. 

(i) 'Be sure that the overflow tube is not entirely closed off. As the 
radiator gets hot, a completely blocked tube causes pressure to build up, 
and the radiator may burst. When inspecting the level of the cooling 
fluid, check to see that the overflow tube is open. 

e. Reassembly. 

(1) Eeplace inlet and outlet fit- Soldering iron. 

tings and filler neck. Rod and heating pot or furnace. 

Clean fittings thoroughly with acid, hold them in place and solder, 
using correct type of soldering rod. 

(2) Test radiator assembly for leaks. 
See / below. 

/. Test. — After the radiator has been repaired or a soldered fitting 
replaced, test the unit as follows : 

(1) Plug inlet and outlet fittings and filler neck. 

(2) Apply air, at a pressure of 6 to 7 pounds per square inch, to the 
radiator through the overflow pipe by slipping the rubber hose from 
the air line over the overflow pipe. 

(3) Immerse the radiator in a, tank full of water and if there are 
no leaks, no air bubbles will appear at the surface of the water. If 
bubbles do appear, the leaky parts should be marked and repaired by- 
soldering. 

g. Repair of radiator grille frame. — Fractures may occur near the 
upper corners of the radiator grille or shutter frame. These fractures 
can be repaired as follows (fig. 62) : 

124 



TM: 9-1709 

chassis and body for scout cars m3a1 31 

(1) Prepare two angle iron reinforcements from 11-inch pieces of 
angle iron (I14 by 1% by %6 inches), as shown in figure 63. Install 
the two reinforcements on the radiator grille or shutter frame in the 
position indicated in figure 62, using the original bolts. 

(2) Weld the cracks which develop at the junction between the 
individual shutter supporting brackets and upright part of the 
grille or shutter frame. Use either gas or electric welding. Grind 
the welding beads on the front surface of the grille or shutter frame 
to produce a smooth, flat front surface. 



RE-INFORCEMENT 

HELD IN PLACE 

BY ORIGINAL BOLTS 




DO NOT WELD BREAKS - 



RE-INFORCEMENTS RIGHT a 
LEFT AS SHOWN IN FT KNOX- 
DRWG. E-155. 



-^iJ 



O 



THIS BREAK IS NOT RE 
PAIRED BUT LOWER SEC- (C^ 
TION IS LEFT IN PLACE 



RA PD 9528 



FiGDRi! 62. — Radiator louver frame. 



(3) Do not weld the fractures which occur in the lower section 
of the radiator grille or shutter frame. Leave the broken off part 
in place, as shown in figure 62, to serve as a spacer. Welding of this 
member will not provide a satisfactory repair. 

h. Installation of assembly. — Tools: 

Hoist. Screw driver. 

%-inch socket wrench. %g-inch open-end wrench. 

%-inch socket wrench. Heavy duty screw driver. 

Pliers. Pail (or water hose). 

(1) Replace radiator. Hoist. 



125 



TM 9-1709 
21 



ORDNAlsrCE MAINTENANCE 



Set radiator in place so that mounting studs pass through holes 
in frame member. 

(2) Connect stay rods. %-inch socket wrench. 

Slip stay rods onto studs at each side of radiator and replace 
holding lock washers and nuts. 



(3) Replace mounting studs at- 


%-inch 


socket 




wrench. 




:;aching parts. 


Pliers. 


J 
1- 


1 


RIGHT SIDE SAME AS 

LEFT SIDE WITH EX- 

\ CEPTION OF LOCATION >- 


3" 




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Place mounting pads, springs, and washers on studs and fasten 
with nuts and cotter pins. 

(4) Replace upper and lower Screw driver, 
radiator hose connections. 

Slide hoses onto fittings and tighten hose clamp bolts. 

(5) Replace fan assembly. l%g-inch open-end wrench. 

%-inch open-end wrench. 



126 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 21-24 

Set fan and bracket assembly in place and replace two screws, 
washers and belts. Tighten up adjusting screw and jam nut. (See 
TM 9-1706.) 

(6) Replace hood. %Q-mch open-end wrench. 

Heavy duty screw driver. 

Set hood in place on top of shutter frame and cowl. Fasten by 
replacing oval head screws and nuts. 

(7) Eefill radiator. Pliers. 

Pail (or water hose). 

Shut off drain cock and fill radiator to bottom of filler neck. 
32. Water pump and fan assembly. — For complete maintenance 
information on these units, see TM 9-1706. 



Section VII 

ELECTRIC LIGHTING SYSTEM; BATTERY AND 
ACCESSORIES 

I'aragraph 

Introduction 23 

Battery 24 

Heater 25 

Horn 26 

Headlamps 27 

Marker lamps 28 

Taillamp 29 

23. Introduction. — The electrical units covered include the bat- 
tery, heater, horn, headlamps, marker lamps, and taillamps. 

a. The entire vehicle wiring diagram (fig. 64), and the lighting 
system wiring diagram (fig. 65), are included in this manual to 
facilitate the tracing and repair of electrical cables and leads. 

h. All electrical equipment installed in the scout cars that is related 
to the power plant (distributor, generator, starter motor, coil, etc.) 
is covered in TM 9-1706, TM 9-1707, and TM 9-1708. 

24. Battery (fig. 66) . — a. Description. — The battery is a Willard 
6-cell, 12-volt model, with each cell containing 25 plates and gen- 
erating 2 volts. 

(1) Construction. — An acidproof container of rubber composition 
is used and the cells are formed by partitions dividing the interior. 
These cells are closed by hard rubber covers, sealed in place, with holes 
for cell poles. Each negative group of 13 plates is permanently con- 
nected at the top by a welded metal strap. The 12 positive plates, 
arranged alternately with the negative plates, are similarly connected 

127 



TM 9-1709 
24 



ORDNANCE MAINTENANCE 



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130 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 24 

in one group by a strap carrying the projecting positive terminal. 
Between each two adjacent positive and negative plates is an insulator 
or separator of specially treated wood or rubber, in sheets, with ver- 
tical ribs on its face. The plates and separators are vertically 
installed on ribs molded in the bottom of the container, with a sedi- 
ment space provided on the bottom. The exposed terminals of each 
cell are joined, positive to negative, by outside connectors welded to 
the terminals on the top battery, thereby connecting the cells in 
series. Vents, with screw-type closure plugs which have small open- 
ings for the escape of gas, permit inspection of the inside of the cells 
and replenishment of the electrolyte and water. Circular rubber 
gaskets around the posts in the covers make the terminals leakproof. 

(2) Functioning. — The battery produces electricity by chemical 
action of dilute sulphuric acid on the plates. The capacity of the 
battery depends upon the size and number of the plates. The latter 
are of stiff lead-antimony alloy castings, mesh or grid-shaped, with the 
openings filled with a paste consisting chiefly of oxide of lead. The 
plates are "formed" by putting them through an electro-chemical proc- 
ess in tanks containing dilute acid, before mounting them in the cells, 
to convert the material on the positive plates into brown peroxide 
of lead and that on the negative plates into gray, spongy, metallic 
lead. With the plates so charged, immersing them in the dilute acid 
in the container will create a potential between positive and negative 
plates. In the discharge of the battery, the sulphuric acid is trans- 
formed into water, and both the lead peroxide and some of the metal 
of the plates are converted into lead sulphate. The discharge must 
be stopped and the battery recharged before all the metal of the 
plates has combined with the acid. 

(3) Specifications. 



Make 


Type 


Model 


Manufacturer's 
No. 


Ordnance No. 


White 
No. 


Willard . _ 


Lead-acid, 
commer- 
cial. 


WH-25-6 


WB-4376 


B156032 (wet charged) 
A226016 (dry charged) 


311936 



Number of cells 6 

Number of plates per cell 13 negative; 12 positive 

Voltage (volts) 12 

Terminal grounded Negative 

Specific gravity fully charged 1.275 to 1.300 

131 



TM 9-1709 
24 



ORDjSPANCE maintek-ance 



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■i:"-'i*.*WP:? 



132 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 24 

Recharge at 1.200. 

Capacity (ampere hours at 20-hour rate) . 204 

Location right side of vehicle on running board, in metal 

compartment 

Dimensions, over-all 20%6 x lO^e x IO14 

Hadio take-off points provided at positive, negative, 6-volt terminals 

Z». Trouble shooting. 



Symptom and proiaile cause 
(1) Failure of engine and 
starting motor to rotate when 
starting switch is closed. 

Loose or dirty terrhinals at 
battery. 

Defective starting switch. 
Battery discharged. 



One or more cells shorted. 

(2) Slow starter speed. 
Loose or dirty terminals. 
Cells dry. 

Batteiy run down. 
Defective starter motor. 

(3) Inability of cell to hold 
charge on open circuit, undue 
heating, little or no rise in voltage 
or specific gravity, or failure to 
gas properly on charging. 

Much sediment or defective 
insulation in cell causing 
short circuit. 

c. Removal of asHernbly. 

(1) Remove metal 



side plates 
ment. 



cover and 
of battery compart- 



ProbaWe remedy 



Clean and tighten terminals. 

Add water to a depth of % inch 
above plates. 

Inspect, clean, repair, or replace. 

Recharge battery. Check genera- 
tor to make sure it is charging 
by inspecting and testing both 
generator and regulator (TM 
9-1706). 

Remove, dismantle, repair or re- 
place battery. 

Clean and tighten. 

Replace water and electrolyte. 

Recharge battery. 

Repair or replace (TM 9-1706) . 



Dismantle and rebuild, or replace 
battery. 



%-inch open-end wrench. 



133 



TM 9-1709 

24 O'ROKANCE MAIKG?'BK;ANCB 

Unscrew three screws BANXlCC with lock washers BECXIK in 
housing top plate DS-PA-3053-T3 and four screws BANXlCC with 
lock washers BECXIK in side plate DS— PA-3053-72. Remove 
plates. 

(2) Detach cables. %-inch open-end wrench. 

Loosen one nut on each terminal, removing negative lead first 
(fig. 67). 

(3) Release battery clamp. %-inch open-end wrench. 

Unscrew two nuts BBBXlC with lock washers BECXIK attaching 
clamp assemblies WI-B8251 at middle of ends to hook bolts WI- 
344980 anchored at bottom of battery compaftment. 

(4) Remove clamp frame from %-inch open-end wrench, 
around top of battery. 

Loosen one or two of the nuts BBBXIB on horizontal clamp frame 
rods and take clamp frame oil. 

(5) Remove battery. None. 

Lift battery out of compartment. 

d. Maintenance. — (1) At least once a week inspect the hold-down 
frame and hook bolts, terminals, and electrolyte. 

(2) Keep the level of the electrolyte 1/2 inch above the plates. Look 
for a leak in the container if the electrolyte appears too low in any 
cell. Add pure (preferably distilled) water. Do not use city, spring, 
or well water unless analyzed and approved. Boiling, filtering, and 
the use of "softening" materials or devices will not remove impurities 
which may injure the battery. Wipe off top of battery and terminals 
afterward. It is best to replenish just before a run when the battery 
will be working. Unmixed water will freeze in cold weather. Re- 
move vent plugs and test each cell with an accurate hydrometer, in- 
serting rubber tube into the electrolyte. The reading for a fully 
charged cell should be between 1.275 and 1.300. If any two cells are 
below 1.200 on two successive testing days, have the entire battery 
tested and fully charged. 

(3) A partially discharged battery may freeze in winter. There- 
fore, in cold weather, the battery should be kept fully charged, partic- 
ularly if the vehicle stands in a cold place for any length of time. 
The freezing point of the electrolyte depends on its specific gravity. 
When fully charged the specific gravity is highest, and at 1.300 the 
electrolyte will remain liquid down to far below zero. 



134 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT OARS M3A1 24 

Freezing temperature 
Specific gravity Fahrenheit Centigrade 

Battery charged 1.285 -96° -70° 

Battery 1/3 charged 1.255 -60° -50° 

Battery 1/2 discharged 1.220 -31° -30° 

Battery 3/4 discharged 1.185 -8° -22° 

Battery normally discharged 1.150 +5° -15° 

Battery completely discharged 1.100 +18° -8° 

(4) A fully charged battery, if it stands idle long enough, will dis- 
charge slowly to a ]:)oint where freezing may ensue. If the vehicle is 




:V. Cable assembly No. 14. 

B. Cable, w/conduit. asseiublj- WI-o54010. 

C. Terminal assembly WB-Q-245. 

D. Cable assembly WI-348739. 

E. Cable assembly No. 6. 



BA KO i}a& 



F. Terminal assemblj \\ I '.ij:_;TlT 

G. Cable assembly No. 14. 
H. Cable No. 6. 

.r. Cable assembly WI-368535. 
K. Cable assembly WI-348738. 



FK3UKK G7. — -Battery cables and terminal, installed. 

stored for a long time without heat in very cold weather, the battery 
should be lifted out and taken to a place where it can be serviced. In 
warm surroundings an idle battery will discharge much faster. After 
being idle for a time and .put back into service, a battery may develop 
buckling of plates and have a shorter life and a much reduced capacity 
to recharge. A battery standing idle should be fully recharged every 
30 days. 

(5) Heating of the battery in service above 110° F. must not be 
permitted. Watch the battery in warm weather and feel the top 



135 



TM 9-1709 

24 ORDNANCE MAJNTENANICE 

connectors. If these are warmer to the touch than the normal temper- 
ature of the human body, check the electrolyte with a thermometer. If 
the temperature reaches 130° F., the battery may be ruined, chiefly 
by buckling of plates, disintegration of the active material, and short- 
circuiting because of damage to the insulators. Whenever the battery 
is found to be getting too warm on a run, turn on some of the lights, 
or cut down the charging rate. If heating continues, check the whole 
electrical system as soon as possible. 

(6) The battery should not stand discharged even if not needed for 
use, 43ecause the acid then attacks the plates and gives them a white 
sulphate coating. This coating is a poor conductor of electricity, 
reducing the capacity for charging and discharging, and lessening the 
effective area of the plates. Sulphation will also appear at the top of 
the plates if the electrolyte is not kept at the correct level (i^ inch 
abovp the plates). Whenever any evidence of sulphation is seen, 
remove the battery and recharge it. It may be restored to working 
efficiency by a low charging rate over a period of several days. 

(7) Never add acid to the battery except when some of it has leaked 
out or spilled ; never dilute the electrolyte with too much water. Put- 
ting in acid to raise the specific gravity will not increase the charge. 
It will render hydrometer readings of no value and shorten the life of 
the battery. When acid has been lost, add acid not above 1,400 specific 
gravity and charge battery or charge empty and then put in a new 
supply at 1.280 specific gravity. If the electrolyte is ever found to be 
too strong or too high, remove some of it and put in more water. If the 
battery is being charged and the acid shows too much strength, 
continue charging and correct iii the same way. 

(8) Check battery terminals and keep them tight. Clean them with 
ammonia or a solution of baking soda in water. Wash afterwards with 
warm water. Coat terminals with petroleum before tightening. Do 
not use cup grease. Inspect ground strap and motor cable and replace 
them if worn or corroded. 

(9) If a new battery is received dry, fill it with electrolyte and 
before putting it into service give it an equalizing charge at half the 
regular charging rate until it gases freely. This step is necessary to 
assure correct specific gravity and voltage. 

(10) (a) To mix acid and water, take only pure or distilled water 
and acid free from impurities. Ordinary commercial sulphuric acid 
is not suitable. Pour water into a lead-lined tank or glazed earthen- 
ware jar; or a vessel of rubber, stone, porcelain, or glass; then add 
acid, and stir with a glass rod or wood paddle (the latter poated with 
lead if acid of 1,865 specific gravity is used) , until thoroughly inter- 

136 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 24 

mingled. Do not use any metal other than lead. Never four water 
into the acid; spattering of the acid may cause injury. 

(6) A good plan is to fill the hydrometer syringe with acid and 
discharge it into the water with the nozzle held under the surface. 
Rinse the syringe with water afterward so that no acid is left in it. 

(o) Allow the mixture to cool, stir again, and test with hydrometer 
and thermometer. If not correct, add acid or water, stir, and check 
again. The temperature of the mixture should be 80° F. when read- 
ings are taken. Never fill battery with hot or cold acid. Cold acid 
is heavier than normal ; warm acid lighter. For each 10° above 80° F., 
correct the reading by adding 0.004; for each 10° below 80° F., cor- 
rect by subtracting 0.004 from the hydrometer indication. The dilute 
acid should not be over 90° F. or below 60° F. when poured into cells. 

{d) When the electrolyte has a specific gravity that is too high (too 
much acid being present) , the lead part of the plates will be attacked 
and the active material thereon, especially the negative plates, will 
be changed to sulphate when the battery is idle. Also the electrolyte 
will then show a tendency to attack wood separators and may car- 
bonize or burn them. On the other hand, if the electrolyte contains 
too little acid, showing low specific gravity, the positive plates will 
be injuriously affected. 

(e),The density of acid usually sold by supply houses and kept 
on hand by battery stations is 1.400. This can also be obtained by 
mixing enough water with sulphuric acid of full strength. , This 
should be reduced to 1.345 specific gravity before using. 

(/) The following table gives the proportions of water and acid 
to be used in mixing: 

Acid table (parts by volume) 



Water and 1.835 specific gravity sulptiuric acid 


Water and 1.400 specific gravity sulphuric acid 


Specific gravity 


Parts water 


Parts 1.836 
acid 


Specific gravity 


Parts water 


Parts 1.400 
acid 


1.200 


13 

11 

13 

11 

8 

5 

2 

3 


3 
3 

4 
4 
3 
2 

1 
2 


1.200 

1.225 

1.250 

1.275 

1.290 

1.300 

1.345 


13 

10 

15 

11 

9 

4 

1 


10 


1.225 _ 


10 


1.250 ___ -_ 


20 


1.275 . -__ 


20 


1 290 


20 


1.300 .^- - 


10 


1.345 -- --- 


7 


1.400 --- - --- 









137 



TM 9-1709 

24-25 ORDNANCE MAINTENANCE 

e. iTistallatiom of assembly. 

(1) Replace in compartment. None. 

Lift battery into compartment with poles in position to receive 
cable, terminals. 

(2) Keplace clamp assemblies. %-incli open-end wrench. 

Put clamp assemblies on top of battery ; tighten nuts on horizontal 
clamp assembly rods. 

(3) Fasten battery in place. %-inch open-end wrench. 

Engage two hook bolts with clamps at bottom of compartment. 
Push upper ends through two clamp assemblies. Attach one lock 
washer and one nut to each hook bolt and tighten. 

(4) Attach cables to poles. %-inch open-end wrench. 
Tighten one nut on each terminal. 

(5) Put on top and side of com- %-inch open-end wrench. 

partment. 

Attach top plate with three screws and lock washers and side plate 
with four screws and lock washers. 

25. Heater. — a. Description. — The heater is an Eaton hot-water 
unit installed on the inside of the dash under the instrument panel. 
The core is connected to receive water from the engine and the motor 
is controlled by a rheostat switch and operated by current from the 
battery. The fan is between the motor and the core. Air to be warmed 
is blown through the latter by the fan. 

(1) Construction. — -The heater housing contains the motor and 
blower of the fan 'assembly, and mounted on the front is the heater 
face which contains the core and the fan. The heater face is supported 
on a frame spaced away from the housing, leaving the heater open at the 
fan for admission of air to the core. Extending from the core through 
the dash^re a pair of tubes connected by hose to the water pump and 
to the engine at the radiator outlet fitting. The outlet fitting contains 
a shut-off valve to control the flow of water from the engine to the 
heater. 

(2) FvMctioning. — ^With the engine running and the water in the 
cooling jacket heated, some of the water is diverted through the core of 
the heater. To warm the vehicle, the rheostat switch on the instru- 
ment panel is turned to connect the motor to the battery and set the 
fan in motion. Air is circulated by the fan over the heated core and 
is warmed. 

138 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 25 



(3) Specifications. 



Make 


Type 


Model 


White No. 


Eaton Manufacturing Co 


Hot water 


Electric 


368288 



Check connections and switch. 
Check and adjust or repair motor. 



Clean hose and flush core. 
Open valve. 



Model Motor fan. 

Fan Six blades. 

Controller switch Rheostat. 

Operating voltage 12-13 volts. 

Operating current 6 amperes (at battery). 

h. Trouble shooting. 

Symptom and probable cause Probable remedy 

(1) Failure of motor to run 
when switch is closed. 

Broken lead or ground. 
Trouble in motor. 

(2) Failure to heat with fan 
running. 

Obstructed hose or core. 
Shut-oflF valve closed. 

0. Removal of assembly. 

(1) Detach hose connections. Screw driver. 

Close shut-off valve WI-375229 at top of engine. Loosen two 
hose clamps WI-375226 at heater tubes and disconnect hose WI- 
375230. Loosen two similar clamps at engine to remove hose for re- 
placement purposes. 

(2) Disconnect motor lead. None. 
Remove cable from connector WI-331080. 

(3) Remove heater from dash. %g-inch open-end wrench. 

Remove three nuts BBBXIB, three lock washers BECXIH, 
three plain washers BEBXlH, mounting heater to dash and remove 
heater WI-368288. 
- d. Disassembly. 

(1) Detach heater front. Screw driver. 

Remove four screws and remove heater case front WI-375215. 

(2) Remove core and square None, 
spacer band. 



139 



TM 9-1709 

25 OKDNANCE MAINTENANCE 

Kemove core WI-375213 and spacer band from heater by hand. 

(3) Kemove fan and motor. ^g-ii^ch open-end wrench. 

Remove two nuts Wl-375218, two washers WI-375217, two plain 
washers and remove fan and blower assembly WI-375214, and motor 
assembly WI-375212. 

(4) Detach fan and wheel as- Screw driver, 
sembly from motor. 

Remove setscrew from hub of fan and remove fan and blower 
assembly WI-375214 from motor assembly WI-375212. 
6. Maintenance and adjustments. 

(1) When engine and radiator are flushed, disconnect heater hose 
from engine and wash core. Flush with air pressure if core seems 
clogged. Watch core and hose for possible leaks. Keep hose clamps 
at core and engine and nuts on mounting studs tight. 

(2) Make sure fan is secured firmly to motor shaft and motor 
secured to housing. 

(3) Take motor out of housing and lubricate bearings regularly. 

(4) The commutator and brush should be kept clean and the 
motor otherwise inspected, tested, and repaired in the same way as 
the starting motor. 

/. Reassemhly of components. 

(1) Attach fan. . Sci-ew driver. 

Put hub on front end of motor shaft and fasten setscrew. 

(2) Mount motor and fan. %6-inch open-end wrench. 

Insert motor in housing, pass ends .of bolts through rear, and put 
on two plain washers, two lock washers, and two attaching nuts. 

(3) Replace core and square None, 
spacer band. 

Mount band in frame at front of housing; place core over it. 

(4) Replace heater front. Screw driver. 

Attach heater case front over core ; insert and tighten four screws. 
g. I'nstallation. 

(1) Mount heater on inside of %6-inch open-end wrench, 
dash. 

Pass tubes of core outward through holes in dash. See that 
spacers are on three attaching studs of housing; slip studs through 
holes in dash. Attach plain and lock washers and nuts at front of 
dash and tighten nuts. 

140 



TIE 9-1709 

CHASSIS AJSTD BODY FOK SOOUT OARS M3A1 25-36 

(2) Connect heater to engine. Screw driver. 

Slip hose ends on tubes in front of dash and replace hose clamps. 
Mount hose in supporting clips and tighten nuts on screws. 

36. Horn. — a. Description. — The horn is a dual Delco-Eemy vibra- 
tor type unit. It consists of two electromagnetic units, with one pro- 
ducing a high and the other a low note, mounted close together on 
separate brackets on the engine side of the dash below the air cleaner. 
The brackets, mounting screws, and component parts of the two units 
are interchangeable except for the diaphragm and collar assemblies. 

(1) Construction (fig. 68). — {a) Each unit has a round base, shaped 
like a shallow inverted pan, with an out-turned rim to engage the edge 
of the diaphragm. The base and diaphragm are attached by screws to 
the top of the collar assembly to hold the diaphragm over the sound 
channels. The middle of the base has an opening in which are placed 
a pole-piece, an electromagnetic coil and a flat plate armature. The 
base and armature are parallel. The pole is E-shaped witli three polar 
projections and three polar faces. The magnetic coil surrounds the 
middle one and is placed so that all three projections are presented to 
the armature. The middle projection has a bore for a stud to connect 
the armature and diaphragm together. The pole-piece has angle- 
shaped side plates, and is secured to the base by studs passing through 
holes in the side plates. Nuts on the studs hold the plates fast. 

(5) Mounted on a bracket secured to the base is a fixed grounded 
contact support and point. Engaging it is a movable point on a flat 
insulated spring, which is also fixed to the bracket and is actuated by 
the armature, when attracted by the coil, to separate the electric contact 
points. The base also mounts a resistance in series with the coil, but 
the fixed and movable contact points from a shunt circuit to ground 
between the coil and the resistance. A "shell" or cover, fastened to a 
bracket spanning the tOp of the collar assembly, houses the electro- 
magnetic coil and armature. 

(<?) The horns are controlled by an electromagnetic relay mounted 
on the front of the dash close to the horns. The relay consists of a 
coil having one terminal connected to the battery and the other to 
the horn button at the upper end of the steering column. Branch wires 
in parallel lead from a fixed and a movable terminal, controlled by 
the relay coil, to the two electromagnetic coils of the horn units. 

(2) Functioning. — Pressure on the horn button closes the relay 
circuit, bringing the terminals of the I'elay together, and closing the 
circuit to both horns. Current passes through the magnetic coils, 
through the contact points adjacent the armatures, then to ground. 
The horn electromagnets are energized and attract the armatures, 

141 



TM 9-1709 
26 



OKDNANiCE MAIaS^ETCANCE 




RA ID; 621 3, 



142 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 26 



r Screw DB-1865938. 
A.i Nut AZ14449. 

[Washer, lock, DK-103319. 

fSerew DR-18g3070. 
B.i Washer, lock, 1.18874. 

iNut DR-1848521. 

(Low note DR-18T861.5. 

C. Collar aesombly j^.^j^ ^^^^ DR-1878ei8. 

D. Nut DR-821204. 

E. Lead assembly DR-1885891. 

F. Armature DR-1864082. 

G. Nut DR-1842784. 



H. Nut, lock, DR-120614. 

J. Stud DR-1872634. 

K. Insulation DR-1858675. 

L. Support and point assembly DR-1881054. 

M. Rivet DR-1875430. 

^, fScrew DR-1S64099. 

'^■iwiisher, lock, DR-802729. 

P. Connector DB-1858677. 

Q. Coil assembly DH-18T4fiC0. 

R. Nut DR-187240S. 

S. Plate DR-1874156. 

T. Base assembly DB-1880532. 



FiauuK 68. — Horn assembly. 



143 



TM 9-1709 
26 



ORDNAKCE MArNTEIs'ANCE 



which break the direct shunt connections to ground, and include the 
resistances in the horn electrical circuit. As a result, the current falls 
off and the electromagnets are momentarily weakened. This make- 
and break-circuit causes the armatures to vibrate rapidly, imparting 
motion to the diaphragm and producing sound in both horns. 
(3) Specifications. 



Make 



Type 



Model 



Manufacturer's 
No. 



Ordnance 

No. 



White 
No. 



Delco-Remy . 



Electric vibrator- 

High pitch 

Low pitch 



DuaL 



DR-188056G 
DR-1999526 
DR-1 999525 



A2 14451 

C74054 

C74053 



353752 
353754 
353753 



Components : 

DK-1999526 1 high note horn. 

DE-1999525 How note horn. 

Parts : 

Interchangeable for both horns, except diaphragms and 
spiral air column collar assemblies. 

Control Through outside relay coil and horn button switch. 

Operating voltage 12 volts. 

Current 23 amperes (at battery). 

h. Trouble shooting. 
Symptom and proiaMe cause Probable remedy 

(1) Failure of horns to operate. 

Horn button switch orrt of Repair or replace (See sec. XII).- 
order. 



Horn relay out of order. 
Horns out of order. 



Loose or open connections. 



Repair or replace. 

Check armatures, springs, studs, 
and terminals. Make sure studs 
are properly fixed to dia- 
phragms. Adjust nuts on base 
studs to raise or lower pole- 
pieces to correct armature air 
gaps. Adjust nuts on top of 
studs for correct operation of 
movable terminals. 

Check cables and terminal screws 
at horn button, fuse block, horn 
relay and horns. Replace 20- 
ampere fuse if necessary. 



144 



TM 9-1709 

CHASSIS AJSfD BODY FOR SCOUT CARS M3A1 36 

Battery weak. Charge or replace. 

Ground between horns and Check and repair cables and insu- 

relay, or at relay coil. lation. 

Grounded coil or terminals Check and clean terminals; re- 
in horns. move and test coils. 
(2) Horns irregular or weak. 

Battery weak. Charge or replace. 

Amature air gap incorrect. Raise or lower pole and coils to 

correct gap. 
Worn or dirty terminals. Clean terminals of horn relay and 

horn button switch, and inside 
horns. 
Loose connections, ground- Check wires and insulation and 
ed cable, or partial open tighten terminal screws, 
circuit, 
Nuts on armature studs at Adjust nuts and tighten, 
diaphragms loose or out 
of correct position. 
Obstruction in sound chan- Check screen at mouth of trumpets 
nels. or collar assemblies. Clean in- 

side sound channels, removing 
screens if necessary. 

c. Removal of assemhly (fig. 69) . 

(1) Remove horn units. %6-inch open-end wrench. 

Remove two nuts BBBXIA and two lock washers BECXIG hold- 
ing each horn unit to bracket and remove units. 

(2) Disconnect cables from Medium-sized screw driver, 
horns. 

Remove top screw DR-1853975 from shell and remove shell DR- 
1853944 from each horn. Remove terminal screw DR-1864099 and 
Jock washer DR-802729 and remove cables. 

d. Disassembly of components (fig. 70). — Tools: 

Screw driver. %-inch open-end wrench. 

%6-inch open-end wrench. ^-inch open-end wrench. 

%6-inch open-end wrench. Soldering iron. 

(1) Remove strap bracket from None, 
base. 

Disengage ends of bracket DR-1850660. 

(2) Remove base, stud, and Screw driver. 

bracket assembly and diaphragm %g-inch open-end wrench, 
from collar. 

477229°— 42 10 145 



TM 9-1709 
26 



ORDNANCE MAINTENANCE 



Remove two mounting screws DE-1865938. Remove four nuts DR- 
1843521, four lock washers DE-1188'r4, and after lifting off base 
assembly DR-1880o32, remove four screws DR-1853920. 

(3) Remove diaphragm from '^/{g-mch. open-end wrench, 
aramature stud on base assembly. 

Remove nut BBBXIA and lock washer BECXIG from armature 
stud. Remove washer DR-1865880, high note diaphragm DR-ISTSBIG 




A. Connector UM-2321, 

B. Bracket WI-3159B1, 

C. Relay DR-1116781. 



,..__„ ^,. RA PD 6220B' 

fHolt A225924. rBolt A225979. 

D.) Nut A225946. E.J Nut A21o243. 

[Washer, lock, BECXIG, [Washer, lock, BECXIG. 

PiuuHK 60. — Horn assembly, iustalled. 



or low note diajDhragm DR-1878815 and two washers DR-18o6598 
and DR-1855396. 



(4) Separate armature 
from coil. 



stud 



i%g-inch open-end wrench. 

%-inch open-end wrench. 

y2-inch open-end wrench. 
Remove lock nut and contact support nut. Remove stud DR- 
1872634 and remove clamp plate DR-18Y4156 and nut DR-1842784 
from top of armature. Remove armature assembly DR-1864081. 



146 



TM 9-1709 

CHASSIS AND BODY TOR SCOUT GARS M3A1 26 

(5) Remove coil assembly from ^e'inch open-end wrench, 
base assembly. 

Remove three nuts DR-821204 from studs on base and remove 
field coil w/pole DR-1874:660. The leads remain connected to base 
assembly. 

(6) Detach coil and pole-piece Soldering iron, 
froin base. 

Melt solder at coil terminals. 

e. Maintenance and adjustments. — (1) Mount armature securely. 
If loose over magnetic coil, turn armature stud from lower end to 
tighten nut above clamp plate, and bind nut, clamp plate, spring, 
armature, and top of stud closely together. 

(2) If armature air gap is too small or large, set nuts on studs 
of base to hold pole assembly with three polar faces about %2 inch 
from armature (figs. 71 and 72). Keep these nuts tight so that pole- 
piece and coil are at all times firmly mounted on base. 

(3) If aramature stud has any play at diaphragm, the latter will 
not vibrate properly. Keep nut on lower end of armature stud tight 
to prevent this. 

(4) When stud is tight at armature and diaphragm, the fixed and 
movable terminals above the armature must be in contact. If sepa- 
rated, adjust operating nut and lock nut until points are closed. If the 
points are not clean, rub them with a thin fine-cut file. 

(5) If leads of coil are broken or disconnected, solder the ends 
to the terminals on the bracket supj^orting tlie armature terminals. 
Examine coil to see if insulation is intact. Test for ground, if neces- 
sary, and replace pole assembly and coil if the coil is damaged. 

(6) Keep base assembly screwed tightly on collar, and shell secured 
firmly; horn should also be attached -tightly to support bracket to 
prevent rattling of parts. Inspect frequently by lifting shells. 

/. Reassembly (fig. 70). — Tools: 

yie-inch open-end wrench. 3/^-inch open-end wrench. 

%6-irich open-end wrench. Soldering iron. 

%-inch open-end wrench. Pliers. 

(1) Replace pole assembly in %6-inch open-end wrench, 
base assembly. 

Hold up flat armature spring. Slip pole assembly under spring 
sideways on base studs. Replace three nuts on base studs. 

(2) Attach leads of coil to Soldering iron, 
terminals at bracket base. 

Solder leads and terminals together. 

147 



TM 9-1709 
26 



O'R'DISrANCE MATNTETCANCE 




TM 9-1709 

CHASSIS A3Sro BODY FOE SOOUT OARS M3A1 26 




C OS OQ ri p > & X' 



<i 05 d Q H &; 6 

<) 33 y Q H Bi o 






's -s* 



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5 CD ' 



t-j O fe ffi 

: r< K3 o? 2 



SO 



g +j OD j5 a> 



m Z 



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,- 9 E £ 



I 

O CO 

2 



a 3 



I o r 

a) pi 7 — 

sQ « p." 




,05 CH Z 

pa cj Q H fa d ri 



« J S &■ 



149 



TM 9-1709 
26 



OKDlSnANCE MAINTENANCE 



(3) Assemble armature, stud %(;-iiich open-end wrench, 
binding piece, and clamp plate 
with coil and pole. 

Lay armature on upper faces of pole-piece under spring. Put 
clamp plate on top between armatui'e and spring. Lay binding piece 







;. , .^.. ■ _..;j£:";::^ ' :. :,£--.::^ RA pd;6212: 

FiGUKB 71. — Horn air gap aajustmenC. 

on clamp plate. Pass armature stud from below through central hole 
in pole-piece, through hole in armature, holes in spring, and clamp 
plate into threaded hole of binding piece. Apply wrench to lower 
part of hexagonal surface of stud and tighten. 

(4) Connect diaphragm to ar- %6-ii^ch open-end wrench, 
mature stud. 

Slip plain washer upon lower end of stud against shoulder. Add 
diaphragm washer, then thrust end of stud through center hole in 
diaphragm. Put on remaining diaphragm washer and lock washer. 
Keplace nut. 

(5) Connect armature stud at %-inch open-end wrench, 
upper end to vibrator spring bear- i/2-inch open-end wrench, 
ing movable terminal point. 

150 



IM 9-1709 

CHASSIS A2fD BODY FOR SCOXJT CARS M3A1 26 




RA r»D 62!!: 



it'iGURK 72, — Horn air gap adjustment. 



Put operating nut on ujjper end of armature stud. Screw down to 
engage terminal spring. Contact points must not be separated. Apply 
lock nut. Tighten both. 

(6) Check position of pole faces None, 
for armature air gap. 

Adjust pole assembly by setting nuts on base studs so that its three 
polar faces are about 1^2 inch below armature. 

(7) Secure base assembly with %g-inch open-end wrench, 
pole-piece, coil, armature and dia- 
phragm to collar assembly. 

Apply four screws, four lock washers, and four nuts and tighten. 

(8) Replace screen and band Pliers, 
over mouth of collar assembly. 

"Stake" or press band in six places over rim of collar assembly. 

(9) Attach bracket to top of None, 
base. 

Engage ends of bracket with notches in base. 

151 



TM 9-1709 
26-27 



ORD'N'ANCE MAINTETs^ANCE 



g. Installation of assembly (fig. 69). 

(1) Mount unit on support Screw driver, 
bracket. 

Insert two mounting screws through holes in base and collar assem- 
bly and in bracket. Replace two lock washers and nuts. 

(2) Connect cable. Screw driver. 

Set terminal in place and replace screw and lock washer. 

27. Headlamps. — a. Description (fig. 73). — The headlamps are 




I^-l'il-l!llL» !!!>' ill! il 



HA PD 6219 



mounted on the front fenders with separate brush guards to protect 
the lenses. Each lamp body houses a reflector and an electric lamp 
with two filaments, one for the upper beam and the other for the 
depressed beam. The controlling device for the depressed beam is 
a foot dimmer switch on the floor near the foot pedals of the vehicle. 
(1) Construction (fig. 74). — (a) The casing or body has a threaded 
stud which enters an inclined adapter on top of the fender and is 
held in place by a nut with washer under the fender. Inside the 

152 



TM 9-1709 

CHASSIS AND BODY FOB SOOUT OARS M3A1 27 

casing is a reflector, which carries a double-filament electric lamp at 
its center. The reflector fits into the front of the body, against the rim, 
with a "cycleray" lens set in front. The lens is supported and held 
tight by retaining springs or clips in a split molding with a binding 
screw at the bottom. A clip in the door locates the lens in correct 
position. 

(&) Between the reflector and the back of the casing is the interior 
wiring assembly consisting of two sockets, one attached to the rear 
of the reflector in line with the lamp, and the other fastened in the 
rear end of the body, opening outward to receive the cable terminal 
plug. Each socket contains two contact points. In the socket on the 
reflector each point engages with a terminal of one of the filaments 
in the lamp, the remaining terminal of the filament being grounded. 
Two separate leads connect each contact point in this socket to one 
of the points in the rear socket, thus providing independent connec- 
tions for the filaments to the supply circuit. 

(2) Functioning. — When the lighting circuits are closed by move- 
ment of the main switch on the dash, the circuit is closed through 
lower filaments of the lamps. The upper beam is then projected from 
the lamps. This beam is for use oii unlighted highways, outside of 
towns. When passing an approaching car or in towns or cities, the 
footswitch should be used to bring the depressed beam into play. 

(3) Specificafdons. 



Make 


Type 


Mode! Manufacturer's 
No. 


Ordnance 

No. 


White 
No. 


Guide lamp _. 


Cycleray 


364~G 


GL-925094 


C85584 


368613 



Operating voltage 

Current at lamp : 

High beam 

Low beam 

Electric lamp 

Mounting 

Candlepower 

Size of lens 

Lens and retaining ring- 
Reflector 

Wire assembly 



12-16 volts. 

2.25. 
1.5. 

2-filament double contact. 
Detachable. 
21-31. 
614 inches. 
Removable. 
Removable. 

Nondetachable from casing un- 
less wires are disconnected. 



153 



TM 9-1709 
27 



OEDNANCE MAINTENANCE 




A. Gasket Bl(i7U25. 

B. Reflector B184212. 

C. Lamp A186626. 

• 1). Spring B185237, 

E. LensC74114. 

F. MoMinff assembly B167672, 

G. Screw A214506. 



RA PD 3576 

H. Nut BBBXID. 

J. Washer, lock, BKCXIL. 

K. Washer B1C7823. 

L. Wiring assembly B1 (i7027. 

M. Spring B151378. 

X. Body assembly CSoOOfl. 



Figure 74. — Hoaillamp — sectionalized 



154 



TM 9-1709 

CHASSIS AND BODY FOE SCOUT GARS M3A1 27 



i. Trouble shooting. 
Symptom, and probaWe cause 
(1) Failure to illuminate with 
main switch in service position. 
Burned-out lamp. 
Battery disconnected or 

terminals corroded. 
Batterv exhausted. 



Probable rem^edy 



Replace lamp. 

Check battery cables and repair or 

replace. 
Recharge battery. 




PD 3467B 



A. Wiring assembly GL-3080332. 

B. Spring GI^912825. 



C. Body assembly GL-5932226. 

D. Gasket GL-921789. 



FiGHKE TS.^HeacUamp details. 



Dimmer switch inoperative. 



Broken or grounded connec- 
tion. 

Main switch out of order. 
Lamp turned in socket. 

Generator brush connec- 
tions loose. 



Check and adjust dimmer switch 
and make sure connections are 
correct. 

Check insulation on wires in cir- 
cuit to main switch and 20- 
ampere fuse on fuse block. 

Repair or replace switch. 

Detach and reinsert with top up- 
permost. 

Repair connections. 



155 



TM 9-1709 

27 OBDNANiCE MMMTENIANiCE 

(2) Faint illumination. 

Lenses dirty. Remove and clean lenses. 

Reflector tarnished. Remove and polish. 

Electric lamps blackened Replace lamps. 

inside. 
Battery weak. Recharge battery. 

Low voltage at bulb socket. Check with voltmeter and correct. 

Check and repair. 
Loose defective or corroded 

connection in wiring cir- 
cuit. 
Corroded or loose battery Check, clean, and tighten. 

terminals. 
Defective connections and Clean and tighten all parts. 

high resistance at light 

switch. 
Generator brushes loose. Set brushes. 
Poor contact of lamps in Insert bulbs into sockets correctly. 

sockets. 

(3) Lamps going off and on or 
flickering. 

Loose wire or ground con- Check wires and insulation, repair, 
nection. and tighten. 

(4) Lamps dimming as engine 

speeds up. 
Wires reversed at gen- Check generator leads, 
erator. 

( 5 ) Illumination too bright and 

bulbs burning out. 
Loose or corroded wire con- Check, clean, and tighten wire and 

nection at generator, am- terminals. 

meter, or battery. 
Faulty operation of current Check and adjust regulator coil 

and voltage regulator. armatures. 

(6) Beams distorted or di- 
verted. 

Bent or sprung reflector. Replace reflector. 

Lamps improperly mounted. Adjust and aim correctly. 

c. Remioval of assembly. 

(1) Detach cable. None. 



156 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 27 

Twist plug by hand and extract from socket at rear of casing. 

(2) Dismount from fender. %-inch open-end wrench. 

Kejuove one nut BBBXID, lock washers BECXIL, and one bearing 
washer GL-912206 from stud on under side of fender, and lift off 
headlamp. 

d. Disass&rnbly (fig. 74). 

(1) Remove molding. Screwdriver. 

Remove one screw GL-117108 at bottom of molding. Detach retain- 
ing molding GL-920370 and lens GL-918831. 

(2) Separate lens from mold- None. 
ing. 

Pull out two lens retaining springs GL-914255 and remove lens 
GL-918831 from molding. 

(3) Remove electric lamp. None. 
Turn and pull out electric lamp GL-125984. 

(4) Remove reflector. None. 

Take reflector GL-918834 and gasket GL-921789 out by hand. 

(5) Liberate sockets. Cutting pliers. 

Screw driver. 
Push wires out and cut terminals off wiring GL-5930332 in one 
socket, preferably the rear one. Withdraw wires at open end. Re- 
cover two springs GL-209572 and insulating socket washer GL- 
921092. With screw driver, loosen retaining spring GL-912825 on 
rear socket in casing and push socket out at rear. Pull front socket 
mounting pins by hand out of notches in edge of central opening 
of reflector and dismount from socket. 

e. Maintenance and adjustments. — (1) Keep lenses clean and wiped 
and replace electric lamps when the bulbs begin to turn dark or black 
inside. Polish reflectors with a soft cloth and rub from rim to center. 
Do not use an abrasive. Replace reflector if it is sprung or bent. 

(2) The focus of each headlamp is fixed. Adjustment of head- 
lamps can best be made with headlamp tester. If no tester is on 
hand, place vehicle with headlamps 25 feet from a smooth vertical 
surface such as a wall or door, preferably of light color (fig. 76) . The 
centerline of the vehicle should be perpendicular to this vertical sur- 
face. Draw a horizontal line on the vertical surface 3 inches lower 
than the height of lamp centers above the floor. Locate a midpoint 
on this horizontal line at which the projected centerline of chassis 



157 



TM 9-1709 
27 



ORDjSTAjS'CE MAXNTEIvAKiCE 



intersects. Measure distance between lamp centers and divide this 
distance equally on the horizontal line at either side of midpoint. 
Then draw two vertical lines across the horizontal line directly ahead 
of each lamp center. 

(3) The inclined adapter or bracket piece between the headlamp 
and the fender has a rounded top fitting against a concave seat on the 



CENTERLINE AHEAD-, 
OF LEFT HEADLAMP-f 

HEADLAMP LEVEL 




(-DISTANCE BETWEEN 
■^HEADLAhflPS 



IrCENTERLlNE AHEAD 
^OF RIGHT HEADLAMP 

I [-HEIGHT OF CENTER 

LOF HEADLAMP 



•VEHICLE AXIS 



® Headlamp aiming chart. 



CENTERLINE AHEAD - 
OF LEFT HEADLAMP- 

CENTERLINE THRU 
HOT SPOT- 



HOT SPOT- 




■€, 



—CENTER LINE 
ACROSS FRONT 
"-OF HEADLAMPS 



CENTERLINE AHEAD 
OF RIGHT HEADLAMP 



VEHICLE AXIS 

■—HEADLAMP LEVEL 
^ fl-FOR ALL VEHICLES 



-AIM RIGHT LAMP 
'— SAME AS LEFT 

RA PD 6366 



® Headlamp aiming pattern. 
Figure 76. — Headlamp adjustment. 



bottom of the casing, and a bore larger than the outside diameter of 
the supporting stud affixed to the casing. Thus the adapter has a 
little play on the stud when loose. If the nut on the stud is unscrewed 
a bit, the adapter can be pushed back and forth so that the inclination 
of the headlamp is changed slightly when the nut is tightened again. 



158 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 27 

Switch on high beams in headlamps and cover one lamp while adjust- 
ing the other. Loosen nut on lamp supporting stud and aim lamp 
so that beam registers centrally with horizontal line at point of inter- 
section of this line and the vertical line on that side. Then tighten 
nut securely, taking care not to change location of beam pattern on 
vertical surface. After lamp is alined cover its beam and proceed 
in same manner with opi^osite lamp. 

(4) Lighting circuit test data (at battery) . 
Headlight and taillight : 

High beam 12 volts, 4.75 amperes 

Low beam 12 volts, 3.5 amperes 

Blackout lights 12 volts, 1.5 amperes 

/. Reassemily (fig. 74). — Tools: 

Soldering iroii. Medium-sized screw driver. 

Fine file. 

(1) Assemble wire assembly. Soldering iron. 

Fine file. 

Put rear socket into rear end of lamp. Attach circular retaining 
spring. Push wires through bottom of rear socket and out beyond 
open end. Put on encircling springs and insulation in socket washer, 
and solder ends of leads on disk. Smooth off witli file to insure even 
level. Draw springs and insulator disk in. Attach reflector socket by 
jiuUing pins into notches in edge of liole at center of reflector. 

(2) Eeplace electric lamp. None. 

Hold lamp with top uppermost, insert into opening at middle of 
reflector, and turn till narrow part of slots is behind spring-pressed 
beads on pins carried by front socket. 

(3) Eeplace reflector. Xone. 
Fit reflector snugly into front of lamp. 

(4) Put lens into molding. None. 

Place lens into molding and secure with two lens retaining springs. 

(5) Mount molding and lens on Medium-sized screw driver, 
lamp. 

Put molding with lens on front of casing. Adjust with lens locator 
and secure with one screw. 

g. I TVitall at/ion. 

(1) Mount lamp on front fender. %-inch open-end wrench. 

159 



TM 9-1709 
27-28 



ORDN AN CE MAINTEK AK CB 



Push shank on lamp down through adapter. Replace bearing 
washer, lock washer, and nut. 

(2) Connect cable. None. 

Insert terminal plug in lamjD body socket at rear. 
28. Marker lamps. — a. Descriftion (fig. 77). — The two marker 
lamps are mounted on the head lamp brush guards on the front fenders. 

(1) Construction. — ^A clear glass lens, a louver, and a blue filter are 
mounted in front of the electric lamp by a rubber gasket, door assembly, 
and retaining screw. 

(2) Operation. — The marker lamps are lighted when the light switch 
is in its intermediate or blackout position. The louver directs the light 
downward, making it invisible from above. 

(3) Specifications. 



Make 


Type 


Model 


Manufacturer's 
No. 


Ordnance 
No. 


White 
No. 


Guide lamp _ _ _ 


Blackout 


5502-B 


GI^916388 


G85572 


368518 







Lens size 

Electric lamp 

Operating voltage 

Current at lamp 

h. Trouble shooting. 
Symptom and prohnMe cause 

(1) Failure to light when other 
lamps light. 

Burned-out lamp. 
Broken or grounded 

lead. 
Lamp loose. 

(2) Lamps dim. 
Lamps loose. 

Electric lamp blackened. 
Poor connection at socket. 
Ground leak. 

(3) Flickering lamps. 
Loose wire. 
Intermittent ground. 

0. Removal of assembly. 

(1) Disconnect cable. 



1% in- 

3 cp, S.C, Mazda 

12 volts 

0.4 ampere 



ProiaMe remedy 



Replace. 

Repair or replace lead. 

Seat electric lamp properly. 

Seat electric lamp. 
Replace. 
Repair. 
Repair. 

Repair or tighten. 
Repair. 



None. 



160 



TM 9-1709 

CHASSIS A3SID BODY FOR SOOUT CAES M3A1 28-29 

Pull end of cable out of connector DM-2321 under front fender. 

(2) Dismount lamp from head- %-inch open-end wrench, 
lamp guard. 

Remove nut BBBXIB and lock washer BECXIH and remove lamp. 

d. Disassembly of components. 

(1) Remove door assembly. Screw driver. 

Remove door screw BCFX2AH and dismount door GL-5932381. 

(2) Remove rubber gasket, lens, None, 
filter, louver, and electric lamp. 

Remove lens GL-5932167, louver GI^5932169, gasket GL-.5932164, 
filter GL-5932165, and lamp GL-142303. 

e. Maintenance. — Replace bulb if blackened or burned out, clean 
lens, filter, and louver. Check lead and make sure its terminal is 
engaged firmly in connector to circuit beneath fender. 

/. Remsemibly of oomponents. 

(1) Replace electric lamp. None. 
Mount lamp in socket by hand. 

(2) Remount gasket with lens None, 
filter and louver. 

Replace parts by setting in 
place. 

(3) Replace door assembly. Screw driver. 
Set door in place, replace screw, 

and tighten. 

g. Installation. 

(1) Mount lamp on support i^-inch open-end wrench, 
plate of headlamp guard. 

Set lamp in place and replace 
nut and lock washer. 

(2) Reconnect lead in circuit. None. 

Insert snap terminal on lead into connector beneath fender. 

29. Taillamp. — a. Descriftion (figs. 78 and 79). — The left-hand 
taillamp is tlie service stop light, service taillight and blackout tail- 
light. The right-hand taillamp is the blackout stop light and black- 
out taillight. 

(1) Construction (fig. 80). — (a) The body or casing of the left- 
hand lamp houses two electric lamps, the upper containing a single 



477229° -42 11 



161 



TM 9-1709 
29 



O'RDNANCB MAINTTEWANICE 




A. Door assembly A214554. 

B. Body assembly A214556. 

C. Lens B184206. 

D. Lamp A214551. 

E. Louyer assembly A214552. 



i\ Filter A214550. 

G. Gasket A21455S. ■ 

H. Screw A214555. 

J. Wiring assembly A214594. 



® Early model. 
PiODEE 77. — Marker lamp — sectionalized view. 



162 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT OARS M3A1 29 




RA PD S3M 



K. Body assembly GL-59322Sy. 
L. Cover assembly GL-5033122. 
M. Lamp GL-142450. 

© Late model. 
FiGUEE 77. — Marker lamp- — sectionalized view 



N. Screw GL-50;->24.1U. 
P. Gasket GL-5933075. 



-Continued. 



163 



TM 9-1709 
39 



ORDNANCE MAINTENANCE 



RA PD 7383 i 




I , I 7-- i:i-|ii , ill iiii|< 'ii~i III 



RA PD 7384 




I'l' I I L ~ I L< i' 'i!'j.iii'j ju ij.il'. 



164 



CHASSIS AND BODY 



TM 9-1709 

WOR SOOUT OARS M3A1 29 



filament and being one of the blackout taillights, and the lower con- 
tainmg two filaments and being the combination service taillight and 
service stop, light. The latter has a transparent ruby lens in front 
of it. The upper lamp projects its rays out through a clear lens 
having a central vertical black band across its face and a ruby filter 
behind it. Between the clear lens and the ruby filter is a louver 
plate or blackout screen arranged to prevent light from going in an 
upward direction. A horizontal partition in the casing between the 
two lamps sejjarates the casing into two compartments. The upper 
is blackened over its whole inside surface. 

(h) The casing of the right-hand lamp mounts two electric lamps, 
one upper and one lower, each having a single filament. Between 
them is a partition dividing the casing into chambers, both of which 
are blackened on the interior. Over the upper lamp is a clear lens 
with vertical black band across it and a ruby filter behind it. The 
lens for the lower lamp is entirely clear with an amber filter behind 
it. Between the lamps and both filters is a blackout screen or louver 
plate to direct the light downward as it emerges. For both casings 
the lenses are mounted one above the other in a ring-shaped door 
for the casing. A round rubber holder carries the lenses, filters, and 
louver plates, and is pressed into the door so as to hold the lenses 
ygainst their seats around the edges of the lens openings. Screws 
hold the doors in place. 

(2) Functioning. — («) When the headlamps are in circuit, the 
service taillamp is lighted in the lower part of the left-hand casing. 
The circuit is made through the dimmer filament of the lower lamp. 
When the brakes are applied, a circuit is completed to the other fila- 
ment of the same lamp by means of the hydraulic stop light switch on 
the master cylinder of the brake system. The lower lamp then 
brightens, giving the stop signal. 

(J) When the main switch is moved to blackout position, the head- 
lamps and service taillight and stop light are cut out ; and the marker 
lamps and the blackout taillamps in the upper compartments of both 
tail casings are connected in circuit. Wlien the brake pedal is de- 
pressed, the stop light switch is actuated and circuit is completed to 
the blackout stop light in the lower compartment of the right taillamp. 

(3) Specifications. 



Make 


Type 


Model 


Manufacturer's 
No. 


Ordnance 

No. 


White 

No. 


Left-hand guide lamp 

Right-hand guide lamp 


Blackout __ 
Blackout-. 


3006-C 
3006-B 


GL-927181 
01^927170 


C85533 
C85532 


368520 
368519 



165 



TM 9-1709 
29 



ORDNANCE MAINTENANCE 




166 



TM 9-1709 

CHASSIS AND BODY FOE SOOUT CiARS M3A1 29 



S « I" 

i; P g d ^ ^ I S ^ .-•:■ 

■* ^ 1-! ^ ^^ Oi '':■ It: a> c: 

» fe .5 a « ^ <^' ^ ? "^ 



BJ u -^ ■ ^ 



aSgi^cpjcopp! 



C I M 

>n . . i^ GO 

■ I tP M S O 

-ij «' d Q a fe d a >-; m" 



167 



TM 9-1709 

29 ORDNANCE MAINTENANCE 

Left-hand taillamp and stop lamp: 

Lower electric lamp GL-173029 D. C. 21-6cp 

Upper electric lamp GL-142450 S. C. Sep 

Right-hand taillamp and stop lamp : 

Electric lamp GL-142303 S. C. 3 op 

Operating voltage 12-16 volts 

Both casings Demountable 

Ring-shaped doors Removable 

Lenses, filters, louver plates Rubber 

Holders and gaskets Detachable 

Electric lamps and sockets Detachable 

h. Trouble shooting. 

Symptom and proTjahle cause ProhaMe remedy 

(1) Failure to illuminate when 
other lamps light. 

Burned-out lamp. Replace. 

Break or ground in circuit. Check connections back to switch. 

Stop light switch impaired. Check and replace if necessary. 

Lamp loose or improperly Make sure lamp terminals engage 

mounted in socket. socket terminals firmly. 

(2) Lamps dim. 

Lamps loose or incorrectlj'^ Push lamp fully into socket. 

mounted in sockets. 
Electric lamp blackened. Replace bulb. 
Poor connections at socket, Check socket, circuit and insula - 

or ground leak. tion. 

(3) Lamps go out and then on 
again or flicker. 

Loose wire connection or in- Check wires and insulation, repair 
termittent ground. and tighten. 

0. RemovaJi of assembly. 

Detach right-hand and left- %,;-inch open-end wrench, 
hand lamps from vehicle. 

Remove two imts BBAXlA and two lock washers BECXIG holding 
each lamp GL-92n70 (right-hand), and GL-927181 (left-hand), in 
place. 

d. Disassembly of components. 

(1) Detach ring-shaped door Screw driver, 
from front of casing. 

Remove two screws GL-5932417 at front. Take molding assembly 

168 



TM 9-1709 

CHASSIS AND BODY FOE SCOUT CARS M3A1 29 

GL-5932655 off left-hand body assembly GL-5930826 and molding 
assembly GL-5932142 off right-hand body assembly GL-5932130. 

(2) Remove filter holders and None, 
lenses from doors. 

Push out with fingers lower ruby lens GL-5932135, upper clear lens 
GL-5932361, and gasket GI^5932124 from door GL-5932663 off left- 
hand lamp. Lower clear lens GL-5932361 and gasket GL-5932124 
from door GL-5932129 of right-hand lamp. 

(3) Eemove gaskets from doors. None. 

Take gaskets GL-5932123 out of doors by hand. 

(4) Remove filters and louver None, 
plates from gaskets. 

Push out by hand louver GL-5931759 and ruby filter GL-5932127 
from gasket of left-hand lamp ; louver GL-5932186, upper ruby filter 
(}L^5932127, and lower amber filter GL-.5932126 from gasket of right- 
hand lamp. 

(5) Remove electric lamps from None, 
casings. 

Turn and pull out by hand, upper and lower electric lamps GL- 
142303 from right-hand body assembly GL-5932130, upper electric 
lamp GL-142450 and lower electric lamp GL-173029 off left-hand 
body assembly GI^5930826. 

(6) Remove lamp sockets from Medium-sized screw driver, 
casings. 

Remove one screw BCNXlFD and one lock washer EECXID at 
each socket ; take out socket retainer GL-5932133. 

e. Maintena/nce. — Replace electric lamp if blackened or burned out; 
clean lenses, filters, and louvers. Check leads and make sure plug and 
wire terminals are engaged firmly in sockets at casings, to connectors 
under body and to circuit points on switches and junction block. If 
stop lights do not illuminate in braking, first make sure electric 
lamps are good; then test stop light switch as follows: connect one 
lead of voltmeter to each terminal of switch. With brakes off, instru- 
ment should read battery voltage. With brakes on voltage .should be 
zero. If either of these readings is not obtained, replace switch with 
ncAv one. 

/. Reassembly of ccnvponents. 

(1) Remount lamp sockets in Medium-sized screw driver, 
casings. 

169 



TM 9-1709 

29 ORDNANCE MAINTENANCE 

Insert two sockets in each casing and attach four retainers by means 
of four lock washers and four screws. 

(2) Insert electric lamps in None, 
casings. 

Push in and turn by hand upper and lower electric lamps of right- 
hand casing and upper electric lamp and lower electric lamp of left- 
hand casing. 

(3) Place gaskets and lenses in None, 
door. 

Turn doors so that the semicircular half bearing screw holes are in 
top position. Lay two gaskets in doors, making screw holes line up. 
Put in by hand right-hand lamp. Clear lens with vertical central 
dark band in upper opening and clear lens in lower opening. Put in 
left-hand lamps, ruby lens in lower opening, clear lens with vertical 
central dark band in upper opening. 

(4) Assemble filters and louver None, 
plates in gaskets. 

Turn gaskets so that semicircular half bearing screw holes are in 
top position. Put in by hand at rear face of holder. In right-hand 
lamp, insert ruby filter in upper opening and amber filter in lower 
opening. Place louver over filters, making screw holes line up. 
In left-hand lamp, insert ruby filter into upper opening. Place louver 
over filter, making sci-ew holes line up. 

(5) Assemble gaskets and None, 
doors. 

Replace gaskets in doors by hand, with screw holes lining up with 
door screw holes. Present filters to rear of doors, lenses to front. 

(6) Put doors and gaskets back Medium-sized screw driver, 
on front of casings. 

Insert two screws into each door and attach doors to casings, door 
with red lens on casing having one blackened compartment, other door 
on casing having two blackened compartments. 

g. Installation. 

Mount casings on vehicle. %g-inch open-end wrench. 

Put lamp with red lens at left, other lamp at right. Attach two lock 
washers and two nuts to studs on each casing and tighten. 



ITO 



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missing 
from book! 



Page is 

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from book! 



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from book! 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 30 

i-ection. The measuring should be performed with tlie greatest accu- 
racy. It can be done without removing any part of the body from the 
chassis by using a plumb bob and crayon or pencil. 

(h) Place vehicle on a level floor with all tires properly inflated. 

(c) Suspend a plumb bob successively at four points on the frame 
at the opposite ends of adjacent cross members (fig. 83). The plumb 
bob should hang down almost to the floor. When it becomes motion- 
less, mark sharply the floor directly underneath it. Repeat for every 
other part of the frame between cross members. 

{d) Move the vehicle and connect the marks with intersecting 
diagonals. Each pair of intersecting diagonals must connect corre- 
sponding points at the opposite sides of the frame. 

(e) Measure the various diagonals. The length of each two inter- 
secting diagonals should match to within i/g inch. Other crossed 
diagonals may be charted on the floor between difl'erent corresponding 
points and compared in the same way. 

(2) /Straightening. — Heat should not be used when straiglitening 
frames because it weakens the frame members; hence all straightening 
should be done cold. Replace frame members which are bent or 
buckled sufficiently to show strain after straightening. 

(3) Cutting, reinforcing, riveting, and welding. — (a) Whenever it 
is necessary to cut the frame previous to welding, make the cut along 
a diagonal line about twice as long as the width of the rail. Use an 
ordinary ruler to measure and lay out the diagonal. This method dis- 
tributes the weld over a greater area than a cut made straight across 
at right angles to the rail and makes the weld stronger. 

(i) Reinforcements can be made with flat, channel, or angle stock, 
the latter being preferred for side rails. Wherever possible, the rein- 
forcement should extend the entire length of the side rail or at least 
18 inches beyond the driver's compartment cross member. This pro- 
cedure may be impractical in some instances because of the position 
of the attached units and existing cross members. The reinforcement 
thickness should not exceed that of the side rail to be reinforced. 

(c) Reinforcements should be securely riveted whenever possible. 
Hot rivets are preferred, but cold rivets may be used wliere tools of 
sufficient power to set the rivets properly are provided. The diameter 
of the reinforcement rivets depends upon spacing and the number of 
rivets used. Generally, rivets should be from 50 to 100 percent as 
heavy in diameter as the total thickness of the plates to be riveted. 

(d) Electric metal arc- welding is recommended for all framewoi'k. 
Heat of the weld is localized and burning of the material is minimized 



175 



TM 9-1709 

30-32 '0KDN;ANCE MAINITEIslAKlCE 

with this method. Outside edges of all reinforcements used to 
strengthen the frame should be welded to the frame after the rein- 
forcements are riveted on. All unused holes should be filled with 
welding material. The welding rod should be of the same material 
as the frame. 

31. Pintle and tow hooks (fig. 84). — a. Towing facilities. — 
Towing facilities are provided at the front of the vehicle by two tow 
hooks WI-C2419X (left-hand), WI-C2418X (right-hand), and at 
the rear by a standard pintle M7A2. The pintle WI-343632 is attached 
to the frame rear cross member with an additional supporting A-brace. 

i. Pintle removal. — To remove pintle, pull out cotter pin BFAX2AM 
and remove nut BBGX3C and thrust washer A135835. The assembly 
can then be pulled from the vehicle. To replace pintle, reverse order 
of removal. 

32. Roller. — a. Description (fig. 85). — (1) Construction. — (a) The 
roller is made of steel plate rolled to form a tube, with the seam welded. 
Two reinforcing rings, evenly spaced in the roller, are welded along 
their edges to the inside of the roller. Two circular plates, each of 
which has a reinforced tube welded to it at the center, are welded into 
each end of the roller. 

{h) A bushing is driven into each end tube, and the supporting 
shaft bearings are placed in these bushings. Each bearing has a 
square section at the outer end. This slides between guides which are 
riveted to the roller supports at each side of the slots in the front ends 
of the rollers. The roller supports, in turn, are riveted to the front 
of the chassis frame. Each support has a spring stop bracket riveted 
to it at the top and in line with the slot therein. 

(o) The roller shaft j^asses through the bearings and the slotted 
holes in the supports and extends slightly beyond each support. Com- 
pression springs are carried by the guide rods and are compressed be- 
tween a shoulder at the lower end of each guide rod and the spring 
stop brackets. The lower ends of the guide rod press uijon the pro- 
truding ends of the roller shaft and are fixed to the shaft by means 
of tapered pins driven through the guide rod bearings and shaft. 
The upper ends of the guide rods are set into the spring stop brackets. 

(2) Fimctionimg. — (a) The roller is held in the lower extremities 
of the slots by compression springs Avhich allow the roller to move up- 
ward and toward the rear when it strikes any obstruction. The square 
ends of the bearings slide in the guides, hence the upward motion of 
the roller is along a straight line. These ends also prevent the bear- 
ings from turning, so that the roller bushings can rotate on the bear- 



176 



TM 9-1709 

CHASSIS AaSfD BODY FOR SOOTJT GARS M3A1 32 



— ' 


4 




O 




U> 


m 


CO 


w 


a 




U- 




< 




a: 


Q 












O 




o 






-12 



177 



TM 9-1709 
32 



OEDNIANCE MAINfTENlANCE 




178 



TIC 9-1709 

CHASSIS AND BODY FOR SOOUT OARS M3A1 32 

ings. The springs act as shock ■ absorbers and cushion the frame 
against excessive strains. 

(i) The roller is provided chiefly for use in passing over ditches 
and holes. It prevents the front end of the vehicle from digging into 
the farther side of the ditch or hole by striking the bank first and 
turning, thereby helping the vehicle to climb out. 

b. Removal of assembly (fig. 86). — Tools: 



114-inch socket wrench. 
Driving rod. 



Steel drift. 

Hammer. 

Two special clamps. 

(1) Kemove tapered pins hold- Steel drift, 
ing spring guides to shaft. Hammer. 

Drive tapered pins BCFXILK out of roller spring guides WI- 
347346. 

(2) Compress roller springs. Two special clamps (fig. 87). 

ll^-inch socket wrench. 

Set clamps upon supports WI-368510 (right-hand), WI-368509 
(left-hand), and under lower ends of guide rods. Compress springs 



A. 




I Screw BCBX-2CM. 
Nut BBBX2C. 
Washer, lock, BECXIE. 
Spacer WI-347351. 
(-.Screw BCBX2BE. 
I Nut BBBX2B. 
\ VVasher, lock. BECXIP. 
[Spacer WI-347351. 



RA PO 7-H3A 



C. Bracket WI-347338. 

D. Bumperette (left-hand) WI-347321. 

E. Spring WI-347345. 
P. Shaft WI-347344. 
G. Rod WI-347346. 

II. Roller assembly WI-347312. 
.7. Hook (right-hand) C2418X. 



Figure 86. — Roller assembly, installed. 



179 



TM 9-1709 

32 



ORDNANCE MAINTENANCE 



rWF- 




<T> C.R.S. ONE REQ'D. 



<g)-^DIA. l|" LONG. DP-PF DRILL 



<D 



ROD. HARDEN. ONE REQ'D. 



:^ 






>> 



11 



li 



'I 



'I 



II 

Li 



<gV-||DIA.^'' LONG. DP-PF DRILL ROD 



ONE REQ'D. 



9 TAP 



€> 



.S 'DIA. 




RAPO 6241 



ffiGUBB 87.— Front roller spring compressing tool. 



180 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 32 

WI-347345 by turning clamp screws until roller shaft no longer rests 
at lower ends of slots in supports. 

(3) Keniove roller. Driving rod. 

Hammer. 

Support roller and then drive out shaft WI-347344. Lower roller 
"^^1-347311 with bearings and bushings to ground. 

c. Disassembly. 

(1) Eemove guide rods and li/4-inch socket wrench, 
springs. 

Turn clamp screws until compression is removed from springs. 
Kemove guides WI-347346 and springs WI-347346. 

(2) Eemove roller bushings and Puller, 
bearings. 

Pull roller bearings WI-34719 out of bushings by hand and then, 
using puller, remove roller bushings WI-347313. 

d. Maintenance and repairs. — (1) The roller requires little or no 
maintenance unless it is damaged. The bearings should be kept 
free of dirt and oiled during the 1,000-mile maintenance service; use 
oil, engine, seasonal grade. 

(2) If the roller is pierced by shell fire, it can be repaired by weld- 
ing plates over the holes. 

(3) When the roller is damaged beyond repair, it should be removed 
as explained in h and c above and replaced with a new roller. 

(4) If the roller is dissassembled for any reason, check the com- 
pression springs for breaks or permanent set, and if any is apparent, 
replace with new springs. Check the bearings and if badly worn or 
damaged, replace. 

e. Reassemhly. 

(1) Keplace bushings. Bushing driving tool. 

Hammer. 

Drive bushings into roller end tubes. 

(2) Keplace bearings. None. 

Push bearings into bushings by hand. 
/. Installation of assembly. — Tools : 

Special clamp. Hammer. 

li^-inch socket wrench. Wood block. 

(1) Clamp springs and guide Special clamp, 

rods in position. 114-inch socket wrench. 

181 



TM 9-1709 

32-34 OK'DISPANCE MAINITENANICE 

Attach clamp to top of roller support. Place compression spring on 
guide rod and set rod into clamp in line with spring stop bracket hole. 
Turn clamp screws and compress spring until shaft hole in guide rod 
lines up with slotted hole in roller support. Follow this procedure for 
second rod and spring. 

(2) Keplace roller assembly. Hammer. 

Wood block. 

Lift roller into place between supports, making sure that square ends 
of bearings slide into roller guides and bearing holes line up with guide 
rod shaft holes. Push one end of shaft through guide rod. Holding 
wood block against opposite end of shaft, drive shaft through bearings 
and opposite guide rod. 

(3) Eeplace tapered pins. Hammer. 

Drive pins through guide rods and shaft. Remove clamps. 

33. Bumpers. — a. Front iumferettes. — Two bumperettes made of 
steel channel members are provided for the front end of the vehicle 
and are located to the left and right of the roller. Each bumperette is 
riveted to the frame rail and stiffened with gussets at the corners. The 
upper gussets are riveted to both the bumperettes and frame rails. The 
lower gussets are riveted to the bumperettes and bolted to the frame 
rails. No maintenance is required imless the bumperettes are badly 
damaged. In that case they should be replaced or straightened and 
new gusset plates added. 

h. Rear hvmifer. — The rear bumper consists of a steel channel cross 
beam and is bolted in place at the rear of the body with its flat surface 
affixed to supports. It is treated as part of the body and no mainte- 
nance is required. 

Section IX 
FUEL SYSTEM 

Pai-agrapli 

Description 34 

Trouble shooting 8.t 

Fuel tanks i : 3C 

Fuel lines 37 

Fuel pump, carburetor, and air cleaner 38 

34. .Description. — The air fuel system consists of two main fuel 
tanks, a tank fuel gage unit, which incorporates the fuel take-ofi pipe, 
fuel lines, a transfer shut-off cock, combined fuel and vacuum pump, 
carburetor with fuel filter, and an air cleaner. The tanks are located 
on the right and left side of the vehicle under the floor plate of the 



182 



TM 9-1709 

CHASSIS AND BODT FOR SCOUT CAES M3A1 34 

driver's compartment. The filler spout and cap extend through a 
hole in the floor plate and are accessible for filling by opening the 
driver's compartment door. A plug is located at the bottom of the 
tank for draining. The fuel line assemblies extend from each tank 
to the transfer shut-off cock located on the lower right side of the 
engine dash, just below the instrument panel. (Each fuel tank has 
a length of flexible hose connected to the fuel tank take-off tube fitting 
and joining a copper tube line assembly, with a protector loom, which 
extends to the shut-off cock.) From the shut-off cock a flexible hose 
connects with the fuel pump, which is mounted on the lower, rear 
right side of the engine crankcase. A copper tube line assembly with 
a protector loom extends from the fuel pump to the carburetor fuel 
filter. The air cleaner is bolted on the right-hand engine side of the 
dash and is connected to the carburetor air intake by a rubber hose 
and air horn. 

a. Functioning. — An eccentric on the camshaft actuates the fuel 
pump rocker arm and diaphragm. On the suction stroke the fuel is 
drawn from the tank, through the transfer shut-off cock, and into the 
fuel chamber. The return stroke of the pump forces the fuel into the 
carburetor float chamber. When the carburetor float chamber is filled, 
its float valve is closed, thus creating a pressure in the fuel pump 
chamber ; this pressure holds the fuel pump diaphragm in the upward 
position where it will remain inoperative until the carburetor requires 
more fuel. Either tank can be selected to feed the system by simply 
opening or closing the individual shut-off cocks. 

h. Specifications. 



Fuel tanks: 




Carburetor : 




Make 


White Motor Co. 


Make 


Zenith. 


Type—. 


Rectangular sec- 


Model 


. IN-16755. 




tion. 


Type— _. 


Down draft dou 


Location- 


. Under driver's 




ble venting. 




compartment 


Location- 


On intake mani- 




floor plates. 




fold. 


Capacity- 


15 gallons each. 


Air cleaner: 




Fuel and vacuum pump : 


Make 


United Special- 


Make 


A. C. Spark Plug 




ties Co. 




Co. 


Model 


T175-9497. 


Model 


1537105. 


Type— _. 


Oil bath. 


Type—-. 


Mechanical. 


Location- 


Right side oi 


Location- 


On right side of 
engine. 




dash. 



183 



TM 9-1709 






34-36 


ORDNANCE : 


MAINTENANCE 


Fuel filter: 




Three way shut-off cock: 


Make 


. A. C. Spark Plug 


Make Weatherhead Co. 




Co. 


Model—. 210745A. 


Model 


F291X2. 


Type Three-way. 


Type_-__. 


Metallic element. 


Location- Driver's compart- 


Location- 


Attached to car- 
buretor. 


ment. 


35. Trouble shooting. 




Symptom and pn 


ohable cause 


ProiaUe remedy 



a. Excessive fuel consumption. 
Poor carburetor adjust- 
ment. 
Dirty air cleaner. 
Fuel leaks. 

Excessive idling. 
Excessive engine tempera- 
ture. 
Improper control adjusting. 

Brakes dragging: 
Tires underinflated. 
Vehicle overloaded. 

&. Fast idling. 

Carburetor controls stick- 
ing. 
Carburetor throttle sitting. 

Air leaks. 

0. Low fuel pressure. 

Fuel pump diaphragm not 

operating properly. 
Air leaks. 



Check jet sizes against factory 

specifications. 
Clean and renew oil bath. 
Check carburetor float valve fuel 
pump, tanks, all lines and fittings. 
Stop engine during long waits. 
See section IV. 

Inspect choke valve for fuel open- 
ings. 

See section IX. 

Inflate to recommended pressure. 

Load only to rated capacity of 
vehicle. 

Free controls. 

Adjust throttle stop screw and re- 
set idling jet. 

Inspect carburetor to manifold 
gasket; tighten flange nuts. 

Tighten holding screws or replace 

diaphragm. 
Tighten vacuum line fittings, 

check. 



Note. — For more detailed trouble shooting information on fuel system, car- 
buretor, fuel pump, fuel filter, and air cleaner, see TM 9-1706. 

36. Fuel tank. — a. Description. — Two tanks of 15-gallon capacity 
each are provided for the vehicle and are located under the floor plates 
of the driver's compartment. 



184 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 36 

(1) Construction (fig. 88). — The two fuel tanks are constructed of 
sheet steel with reinforced ends. On the bottom of the tank is a boss 
and threaded plug which is removed when draining the tank, and on 
the top is the filler spout and cap. In the cap are two small holes 
for venting the tank. Inserted in the top side of the tank is the elec- 
trically operated tank fuel gage, which incorporates the fuel take-oif 
tube and fitting. The tanks are placed on two mounting brackets 
fastened one on each side of the frame and held in position by two steel 
clamping straps. 

(2) Functoning. — Fuel is drawn from the tank through the fuel 
take-off tube, which is fastened on the flange of the tank fuel gage 
and extends down to within % i^ch of the bottom of the tank. Two 
small holes in the filler cap vent the tank to atmosphere. The tank 
is drained by removing the drain plug located at the bottom of the 
tank. The fuel tank gage float moves with the fuel tank level and is 
geared to a shaft that operates the arm on the rheostat, which controls 
the flow of current operating the dash fuel gage. 

i. Trouble shooting. 



Symptom and prohaWe cause 

(1) Excessive fuel consumption. 
Loose fuel tank outlet fit- 
ting. 

Leak at outlet fitting 

threads. 
Loose fuel tank drain plug. 
Leak in fuel tank. 

(2) Lack of fuel. 

Dirt in filler cap vent holes. 

Dirt in fuel tank. 



Probable remedy 

Tighten fittings. 

Keplace fitting. 

Tighten plug. 
Repair or replace. 

and 



gasket and 
filter fuel, and 



Remove cap 
clean out holes. 

Drain tank, 
refill. 

Inspect fuel tank gage, replace 
or repair. ' 



Incorrect or no fuel gage 
reading. 

G. Removal of assembly. — Tools : 

%6-iiich open-end wrench. 
i%2"iiich open-end wrench. 
(1) Remove fuel line connec- 
tion. 

Disconnect flexible hose assembly held by fuel line flared nut 
WH-105X5 at tank. 



%-inch open-end wrench. 
%6"inch open-end wrench. 



185 



TM 9-1709 
36 



ORDNANCE MAESfTENANCE 




186 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 36 

(2) Disconnect fuel gage wire. i%o-inch open-end wrench. 
Loosen fuel tank gage terminal nut BBAXlA and remove wire. 

(3) Eemove fuel tank straps. ^-inch open-end wrench. 

Kemove four nuts BBBXlC and lock washers BECXIK from straps 
WI-344968 and disconnect strap from tank. 

(4) Eemove fuel tank. None. 
Lift fuel tank from bracket. 

d. DisassenMy. 

(1) Eemove tank fuel gage with Screw driver, 
fuel take-off tube assembly. 

Eemove five screws BCN"X4AE and waslier WI-00442A from gage 
flange and remove fuel gage assembly SW-92763 and gasket WI- 
A25051X. 

(2) Eemove filler cap. Xone. 
Unscrew and remove cap WI-B9510 from tank. 

(3) Eemove drain plug. %-inch open-end wrench. 
Unscrew drain plug WI-A9262X. 

e. Mai/ntenanee mid repairs. — (1) Cleaning. — The tanks should be 
removed and cleaned occasionally. Before attempting to repair any 
fuel tank, clean the tank thoroughly. This is absolutely necessary as a 
safety precaution against the explo^iion of gasoline or fumes remaining 
in the tank. The usual procedure is to fill the tank with a solution 
containing an alkaline cleaner (QMC Tentative Specifications ES-No. 
542) and then flush it out with steam. While flushing, keep all the 
fittings open to drain the sediment and to avoid building up a steam 
pressure high enough to weaken or wreck the tank. 

(2) Soldering. — The repair of fuel tanks is a soldering copper job; 
not a torch job, because of the danger of an explosion when an o]3en 
flame is used. The soldering copper is safe and fast enough if skill- 
fully used. Never use a torch. If there are leaks about a fitting, 
remove it, and clean and retin the joint before resoldering the fitting 
to the tank. Use half-and-half solder. 

(3) Inspect filler cap vent holes and clean, if any dirt is present. 

(4) After filling the tanks, replace the caps to prevent any dirt from 
entering. 

(5) Inspect tank fuel gage float. If a leak has developed, it should 
be repaired by soldering after all traces of fuel and fuel vapor have 



187 



TM 9-1709 

36 ORDNANCE MAINTENANCE 

been removed. If for any other reason the gage is inoperative, the 
unit should be replaced. 

/. Tests {wet method) . — ^After the tank has been removed from the 
vehicle and disassembled, either the wet or air pressure method can 
be used to find any leaks before repairing and to test for leaks after 
repairing. The wet method is as follows: 

(1) Tightly plug all openings except the filler neck. 

(2) Dry entire outer surface of the tank thoroughly with com- 
pressed air and a clean rag. 

(3) Place tank on a bench on top of blocks so that the under side 
can easily be seen witli the aid of an electric light. 

(4) Fill tank with water. 

(5) Insert end of air hose in the filler neck and cover remainder of 
the opening with the palm of the hand. 

(6) Apply air pressure against the water by opening the air valve 
with the other hand for a few minutes. 

(7) Examine entire tank for moist spots where the water was forced 
through. 

g. Tests [air pressure method). — The air pressure method is as 
f olloM'S : 

(1) Plug all openings except the fuel outlet connection. 

(2) Attach loose end of air supply hose to the fuel outlet connec- 
tion by a short-threaded tube. 

(3) Submerge fuel tank in a tank of clean water, or cover the tank 
with a soapy solution. 

(4) Turn on the aii- pressure, but not more than four pounds. 

(5) Draw a ring around each spot on the fuel tank where bubbles 
appear. The bubbles indicate leaks. 

Note. — Some tanks stand considerable pressure, whereas others must be 
handled carefully. A maximum air pressure of four pounds with either method 
of testing is usually sufficient to indicate all leaks. If compressed air is not 
available, improvise a method of producing it, such as using an ordinary tire 
pump. 

h. Reassembly. 

(1) Eeplace drain plug. %-inch open-end wrench. 
Eeplace drain plug at bottom of fuel tank. 

(2) Replace filler cap. None. 
Screw on cap to tank filler spout. 

(3) Replace tank fuel gage Screw driver, 
unit. 



188 



TM 9-1709 

CHASSaS AND BODY F0« SOOUT CARS M3A1 36-37 

Place gasket on gage flange. Insert gage into hole intake, line up 
hole and replace five screws. 
i. Installation of assembly. — Tools : 

3/4-inch open-end wrench. %6-inch open-end wrench. 

1%0-inch open-end wrench. 

(1) Keplace holding straps. s^-mch open-end wrench. 

Place two straps over tank and into holes in bracket and replace 
four nuts and lock washers. 

(2) Connect tank fuel gage 1%2-inch open-end wrench, 
wire. 

Set wire on gage terminal post and tighten holding nut. 

(3) Connect fuel line to tank. %6-inch open-end wrench. 
Connect flared tube nut to tank fuel take-off tube fitting. 

37. Fuel lines. — a. Description (fig. 88) . — The fuel lines connect 
the two fuel tanks with the three-way transfer shut-off cock which is 
mounted on the lower right, engine side, of the dash. A flexible hose 
extends from the shut-off cock to the fuel pump inlet connection. 

i. GoTistr-uction. — (1) The line assemblies connecting the tanks to 
the three-way shut-off cock are copper tubing covered with a protect- 
ing loom. The ends of the tubes are flared to take flared tube fitting 
nuts. Short lengths of metal-lined flexible hose connect the two lines 
to the outlet fittings of the tanks by means of fittings and nuts. 

(2) The bronze three-way transfer shut-off cock has two threaded in- 
lets to take the fuel line fittings from each tank and two valves that cut 
off fuel from the tank not in use (figs. 89 and 90). A single threaded 
outlet connects with the fuel pump line fitting. A flexible hose assem- 
bly connects the fuel pump inlet fitting to the shut-off cock outlet. A 
copper tube assembly with a protecting loom connects the fuel pump 
outlet to the carburetor fuel filter. 

c. Trouble shooting. 

Symptoms and prohdhle cause Probahle remedy 

(1) Leaking lines. 

Split or fractured tube. Replace line assembly. 

Loose fittings. Tighten or replace, if necessary. 

(2) Fuel line feeding slowly or 
not at all. 

Dirt in lines. Remove lines and clean. 

Dirt in three-way shut-off Remove cock and clean, 
cock. . 



189 



TM 9-1709 
37 



ORDNANCE MAINTENANCE 




A. Cock assembly WH— 675G. 

B. Line assembly WI-348731. 

C. Nut WII~105XS. 

FiGunii 89.- 



RA PD 7480 

1>. Hose assembly WI-34872C, 
K. Line assembly WI-348730. 
F. Nut Wn-105X5. 
-Shut-off cooli, installed (engine side). 




COCK, ASS'Y - WH-6757 RA 
FiGUKE 90. — Shut-off cock, installed (compartment side). 



190 



TM 9-1709 

CHASSIS AND BODY FOB SCOUT CARS M3A1 37 

d. Removal. — Tools: 

%6"iiich open-end wrench. i%e-inch open-end wrench. 

%-inch open-end wrench. 1%6-iiich open-end wrench. 

% 6-inch open-end wrench. Screw driver. 

(l)Eemove flexible hose assem- %6-inch open-end wrench, 
blies at tanks. 

Disconnect flexible hose assemblies at right and left fuel tank outlet 
fitting. Then disconnect flared tube nuts WH-105X5 at copper line 
connections and remove hose assemblies WA-80029. 

(2) Discomiect fuel line clips. Screw driver. 

Kemove nuts BBAXIA^ lock washers BECXlG, and screws 
BCNX2CG holding clips WI-27593X and WI-A7047XA to frame and 
remove clips. 

(3) Remove line assembly %-inch open-end wrench, 
(right-hand tank to shut-off cock). 

Disconnect flared tube nut WH-105X5 at shut-off cock fitting and 
remove line assembly WI-348731. 

(4) Remove line assembly (left- i/2-inch open-end wrench, 
hand tank to shut-off cock) . 

Disconnect flared tube nut WH-105X5 at shut-off cock and remove 
line assembly WI-329404. 

(5) Remove flexible hose assem- '^ig-inch open-end wrench. ' 
bly (shut-off cock to fuel pump in- 
let). 

Disconnect flexible hose fittings at fuel pump inlet and shut-off cock 
outlet and remove hose assembly WI-348726. 

(6) Remove line assembly (fuel i^-inch open-end wrench, 
pump outlet to carburetor filter in- 
let). 

Disconnect flared tube nuts WH-105X5 at fuel pump and filter and 
remove line assembly WI-348786. 

(7) Remove three-way shut-off lyig-ihch open-end wrench, 
cock. 1%6-irich open-end wrench. 

Unscrew shut-off cock packing nuts and remove cocks, packing, and 
nuts. Then remove attaching nuts and take out cock WH-6757. 

e. Maintenance and adjustments. — Inspect lines and fittings for 
leaks, fractures, and worn spots. Tighten fittings and flared tube nuts. 

191 



TM 9-1709 

37 ORDNANCE MAINTENANCE 

If, after all fittings have been checked and tightened, the lines continue 
to leak, replace with new line assembly. If standard line assemblies 
are not available for replacement, assemblies can be made from stand- 
ard tube stock as follows : 

(1) Cut tubing to length required. Square ends and remove burs 
and dirt from tubing. 

(2) Cut protector loom to length required and slide on to tubing. 

(3) Place flared tube nut on each end of tubing and flare ends of 
tubing, using a flaring tool (fig. 33) . 

/. Installation. — Tools : 

ii/i 6-inch open -end wrench, %6-iiich open -end wrench. 
i%e-inch open-end wrench. %g-inch open-end wrench. • 
%-inch open-end wrench. Screw driver. 

(1) Eeplace shut-off cock as- n/ig-inch open -end wrench, 
sembly. i%g-inch open-end wrench. 

Set valve in position on dash and replace holding nuts. Then re- 
place cocks, packing, and packing nuts. 

(2) Eeplace line assembly (fuel i/Q-inch open-end wrench, 
pump outlet to carburetor filter in- 
let). 

Hold line assembly in position and connect flared tube nuts to pump 
and filter fittings. 

(3) Replace hose assembly ^g-inch open-end wrench, 
(shut-off cock outlet to fuel pump 

inlet) . 

Connect hose assembly nuts to shut-off cock outlet fitting and fuel 
pump inlet fitting. 

(4) Eeplace line assemblies i/^-inch open-end wrench, 
(shut-off cock to left-hand and 

right-hand tank). 

Hold each copper tube line assembly in position and connect flared 
tube nuts to shut-off cock inlet fittings. 

(5) Eeplace fuel line clips-. Screwdriver. 

Place clips on lines and attach to frame with screws, lock washers, 
and nuts. 

(6) Eeplace right-hand and %6-iiich open-end wrench, 
left-hand tank flexible hose. 



192 



TM 9-1709 

CHASSIS XNV BODY FOR SOOUT CARS M3A1 37-40 

Connect copper tube line flared tube nut to flexible hose fitfing and 
then connect fitting flared nut, at opposite end of hose, to tank outlet 
fitting. 

38. Fuel pump, carburetor, and air cleaner. — For complete 
maintenance information on these units, see TM 9-1706. 

Section X 

INSTRUMENT AND GAGES 

• raranrapn 

General 39 

Iiistniinent cluster 40 

Voltmeter 4] 

Speedometer . . . .. 42 

39. General (fig. 91). — The instruments mounted on the instru- 
ment panel consist of a foui--unit instrument cluster, a voltmeter, and 
a speedometer. The indirectly lighted four-unit cluster assembly is 
mounted in a case at the left center of the panel and is composed of an 
ammeter, temperature gage, fuel gage, and the oil pressure gage. Lo- 
cated at the right center of the panel is the voltmetei'. The speed- 
ometer is mounted approximately in the center of the panel just to the 
right of the cluster assembly. Attached to the back of the speedometer 
case is a bracket which liolds the socket and lamp for the indirect 
lighting of both the speedometer and cluster assembly. 

40. Instrument cluster (figs. 92 and 93). — a. Description. — The 
instruments of tlie cluster assembty are grouped in a circular case 
with the ammeter at the top and the temperature gage at the bottom. 
At the right is the oil gage and at the left is the fuel gage. 

(1) Construct I OIK — (a) The instrimients of the cluster assembly are 
mounted on two semicircular plates attached to the case by four ma- 
chine screws, two in each plate. Mounted on one plate are the oil 
and temperature gages, on the other jjlate are the fuel gage and 
ammeter. Two brackets with nuts, studs, and lock washers attach the 
case to the instrument panel. 

(i) The ammeter, used in conjunction with a shunt, is of the mag- 
netic type, with a permanent magnet operating the pointer. The dial 
is graduated to read +100 to to —100 amperes. Two insulated 
terminal posts connect the generator and battery wires to the instru- 
ment. Two screws fasten the ammeter to the cluster case mounting 
plate. 

(c) The electrically operated fuel gage is of the balanced coil type 
with a pointer dial graduated to indicate "empty-i/4-%-%-full." The 



477229° — 42 13 193 



TM 9-1709 
40 



ORDNANCE MAINTENANCE 




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194 



T35I 9-1709 

CHASSIS AND BODT FOK SOOUT CAES M3A1 40 



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TM 9-1709 

40 



OEDNAKCE MAIKTENANCE 



(2) Functioning. — (a) A'imneter. — The ammeter indicates total 
current discharge ( — ) under any load when the generator is inopera- 
tive and the net charge { + ) to the battery when generator is operating, 
regardless of auxiliary loads. The ammeter does not indicate total 
generator output, although it can be utilized to do so for test purposes 
by shifting the generator lead to the battery terminal of the ammeter. 
The generator begins charging when the vehicle reaches a speed of 
from 7 to 10 m])h and shows a positive ( + ) reading on the ammeter. 




RA fO 621 « 



KiGUUE 118. — Instniinent cluster a.ssen)bly — rear view. 



The charging rate increases with the vehicle speed mitil a maximum 
rate is reached at approximately 25 mph. AA'^ith a fully charged 
battery little or no charging rate will be indicated by the ammeter, 
due to the action of the voltage regulator unit. 

(&) Fuel gage. — The gage indicates level of fuel in tank and is 
operative only when the ignition switch is turned on. The fuel gage 
is operated by the fuel tank unit, consisting of a rheostat and a float 
mechanism. The float element of this unit moves with the fuel tank 
level and is geared to a shaft which operates the rheostat arm. The 
rheostat controls the flow of cui-rent to the fuel gage coils, which move 

196 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 40 

the gage pointer in relation to the quantity of fuel in the tank. The 
fuel tank trsinsfer switch permits the reading of either tank from 
one gage. 

(c) Oil gage. — ^Attached to the oil gage Bourdon tube is a pipe witli 
its opjjosite end coimected to the delivery or pres.sure side of the oil 
l)ump. As the oil pressure increases, the air in tlie pipe is com])ressed ; 
this pressure expands the Bourdon tube ; as the oil jyressure decreases, 
the reverse action occure and the Boui-don tube contracts. This expan- 
sion and contraction of the Bourdon tube actuates the oil gage pointer. 
Oil pressure reading will vary according to operating conditions. Tlie 
oil gage does not indicate the amount of oil \\\ the crankcase. 

{d) Temperature gage. — The temperature gage indicates the engine 
water temperature and is calibrated to read in degrees Fahrenheit. 
The normal operating range under average conditions should be be- 
tween 140° F. to 180° F. The Bourdon tube unit of this instrument 
which actuates the dial pointer is controlled by a low boiling point 
liquid contained in the vapor bulb. As the engine water temperature 
rises the liquid forms a gas, creating pressure in the bulb. This pres- 
sure is transferred by the tubing to the Bourdon tube, which expands. 
As the water temperature lowers, the gas pressure is reduced, contract- 
ing the Bourdon tube. Tliis expansion and contraction of the Bourdon 
tube actuates the gage pointer througli a f)air of gears. 

( 3 ) Specifications. 



Unit 


Malse 


Type 


Manufacturer's 

No. 


Ordnance 

No. 


Wliite 
No. 


Ammeter 


Stewart-Wariier- _ 


Electromag- 
netic. 


SW-105820 




373850 


Fuel gage _ _ 


Stewart- Warner- _ 


Electromag- 
netic. 


SW-G-95622 


A169293 


K95622 


Oil gage 


Stewart-W arner_ _ 


Pressure 


SW-95614 


A169292 




Tempera- 


Stewart-Warner- _ 


Fluid expand- 


SW-G-95620 


B 157037 


340115 


ture gage. 




ing. 









1). Removal of oMemhly. — Tools : 

%-inch open-end wrench. %6"™ch open-end wrench. 
%e-inch open-end wrench. %4nch open-end wrench. 

(1) Remove instrument shield- None. 
ing box cover. 

Remove two wing nuts WI-16896X and take off cover WI-317274. 

197 



TM 9-1709 

40 O'RDNANCE MAIKTENANCE 

(2) Remove temperuture gage %-iiich open-end wrench, 
bulb adapter. 

Loosen temperature gage bulb adapter nut SW-93844 and remove 
bulb froni adapter at engine. 

(3) Eemove oil gage line. ^g-inch open-end wrench. 
Eemove oil line nut located on the back of cluster case. 

(4) Eemove ammeter wires. ^/-f ,;-inch open-end wrench. 
Loosen two ammeter wire terminal nuts BBAXIB and pull out wires. 

(5) Eemove fuel gage wires. %-inch open-end wrench. 
Loosen two fuel gage wire terminal nuts and remove wires. 

(6) Eemove cluster assembly %-inch open-end wrench, 
and mounting bracket. 

Eemove two clustei' assembly mounting stud nuts BBMXlC and 
lock washer BECXlE. Then remove two brackets SW-T4074 and 
lift out cluster assembly SW-96385. 

0. Disassembly . — Tools : 

14 -inch open-end wrench. % g-inclr open-end wrench. 
i%g-inch open-end wrench. Screw driver. 
%-inch open-end wrench. 

(1) Eemove cluster from panel. 
See h above. 

(2) Eemove instruments from ^/^-inch open-end wrench, 
case. Screw driver. ■ 

Eemove two case mounting studs SW-91889 and four backing plate 
screws SW-12389, and lift plates with instruments from case assembly 
SW-95668. 

(3) Eemove oil gage from i%g-inch open-end wrench, 
mounting plate. 

Eemove attaching nut SW-93844 and lift oil gage assembly SW- 
95614 from plate. 
Note — Do not remove temperature gage from plate. 

(4) Eemove fuel gage from %-inch open-end wrench, 
mounting plate. 

Eemove two terminal stud nuts SW-644.59, two lock washers SW- 
5062, and two plain brass washers SW-T7875. Then remove insulator 
SW-91350 and fuel gage assembly SW-G-95622. 



198 



TM 9-1709 

CHASSIS AWD BODY FOR SOOUT CARS M3A1 40 




M O 



199 



TM 9-1709 

40 ORDNANCE MAINTENANCE 

(5) Remove ammeter from %6-inch open-end wrench, 
mounting plate. 

Remove two terminal nuts BBAXlB and insulator SW-91350. 
Then remove three screws SW-75068 and lock washers BECXIC, and 
lift ammeter assembly SW-106820 from plate. 

d. Maintenance and adjustments. — (1) Ammeter. — The ammeter 
requires no adjustments. If the ammeter does not function after the 
electrical system has been checked, replace it. Tests may be made 
to determine current at the ammeter terminal posts with a portable 
ammeter. If the ammeter pointer does not move to discharge ( — ) 
with the lights turned on and the engine not running a faulty am- 
meter is indicated. 

(2) Fuel gage. — If the fuel gage deos not register after the fuel 
tank gage unit has been checked and inspection shows current at the 
fuel gage terminals, replace fuel gage. 

(3) Ternperature gage. — The temperature gage requires no adjust- 
ments and once installed will become inoperative only by the loss of 
liquid caused by leaks, at which time the instrument should be re- 
placed. Check accuracy of the temperature gage by submerging the 
vapor bulb in boiling water. 

(4) Oil gage. — Check oil gage for proper readings. If the oil gage 
indicates improper pressure or no pressure at all this may be due to 
a faulty oil pump, oil line leakage, or to a stoppage. Replace the 
oil gage if it does not indicate proper oil pressure after the engine 
oiling system has been inspected and found in order. 

e. Reassembly. — Tools: 

%6-inch open-end wrench. %-inch open-end wrench. 
%-inch open-end wrench. Screw driver. 

iyi6-inch open-end wrench. 

(1) Replace ammeter on %(j-inch open-end wrench, 
mounting plate. 

Insert ammeter terminal studs in plate holes and replace screws 
attaching ammeter to plate. Slide insulator on terminal studs and 
screw on terminal nuts. 

(2) Attach fuel gage to mount- %-inch open-end wrench, 
ing plate. 

Insert mounting terminal studs in plate holes and replace insulator, 
brass washers, lock washers and nuts. 

(3) Replace oil gage. n/ie-inch open-end wrench. 



200 



TM 9-1709 

CHASSIS AND BODY POiR SCOUT CARS M3A1 40-41 

Insert oil gage mounting fitting in plate hole and replace holding 
nut. 

(4) Replace instruments in case %-inch open-end wrench, 
and bezel assembly. Screw driver. 

Place the two instrument mounting plates in position in case and 
replace screws and case mounting studs. 
/. Installation of assembly. — Tools : 

%-inch open-end wrench. yig-inch open-end wrench. 

%-inch open-end wrench. ^g-inch open-end wrench. 

(1) Install cluster assembly on %-inch open-end wrench, 
instrument panel. 

Place cluster assembly in hole on panel and replace bracket, nuts, 
and lock washers. 

(2) Attach temperature vapor %-inch open-end wrench, 
bulb to engine. 

Insert bulb in adapter and screw on and tighten bulb adapter nut. 

(3) Connect oil line to gage. %6-ii^ch open-end wrench. 
Place line in fitting and tighten flared tube nut. 

(4) Connect fuel gage wires. %-inch open-end wrench. 
Connect wires to terminal posts and tighten nuts. 

(5) Connect ammeter wires. ^g-inch open-end wrench. 

Place wires on terminal posts and replace washers and nuts. 
41. Voltmeter (fig. 95). — a. Descriftion. — -The d-c voltmeter is 
an electromagnetic type with a range of to 20 volts. 

(1) Const')\uition. — The d-c voltmeter consists of a magnet, coil, 
pointer, and dial, which is graduated from to 20 volts. The volt- 
meter is mounted in a flanged case and a retaining clamp ring secures 
the voltmeter to the instrument panel. 

(2) Ftmctioning. — The voltage developed by the battery is meas- 
ured by the voltmeter. A small amount of current passing through 
a high resistance coil, pivoted on the pointer axis, creates a magnetic 
field whose torque reaction operates the pointer. The voltmeter may 
be connected to or disconnected from the system by the push button 
switch located on the panel under the voltmeter. Once the generator 
is operating, checks of system voltage reflect the results of the poten- 
tial generator output rather than that of the battery. The voltmeter 
does not substitute for battery hydrometer reading in determining the 
state of the battery charge. 

201 



TM 9-1709 

41 

(3) Specifications. 



ORDNANCE MAINTEiNAKCE 



Make 


Type 


Manufacturer's No. 


Ordnance No. 


White No. 


Hiokok -Electric 


Electric- 




A 190863 


363725 











i. Removal of asse^nhly. — Tools : 

%-incli open-end wrench. Screw driver. 
i%2"irich open-end wrench. 

(1) Remove voltmeter wires. %-inch open-end wrench. 

Loosen two wire terminal nuts BBMXlC and pull out wires. 

(2) Remove voltmeter. Screw driver. 

1%2-iiich open-end wrench. 

Loosen screw BCNXIFK on case clamp retaining ring holding 
screw nut BBKX2B with wrench. Slide ring off case. Remove 
voltmeter AVI-363725. 

c. Disassembly of components (fig. 95). 

(1) Remove voltmeter from in- 
strument panel. 

Refer to 5(2) above. 

(2) Remove voltmeter media- Small screw driver, 
nisni. 

Remove three screws HK-BA86-1A that attach case to voltmeter 
base and separate mechanism from case assembly. 

(3) Dial and pointer stop. Small screw driver. 

Remove two screws HK-BXloY from dial HK-5607 and take 
off dial and pointer stop. 

d. Maintenance and adjustments. — (1) Replacements.— Li the volt- 
meter fails to give voltage readings after the push button switch 
and the electrical sj^stejn have been inspected, replace voltmeter. 
Replace broken dial glass with case and glass assembly. 

(2) Adjustments. — To set voltmeter pointer to zero, turn adjust- 
ing screw on face of instrument case until pointer is in line with 
the zero mark on the dial. 

e. Reassembly of oonh'ponents. 

(1) Replace s'oltmeter dial and Screw driver, 
pointer stop. 



202 



TM 9-1709 

CHASSIS AND BODY FOiR SOOXJT CARS M3A1 41 




TM 9-1709 

41-42 OKDNANCE MArNTENANCE 

Slide dial under pointer so that the two screw holes are in line, 
insert screws, and tighten. 

(2) Replace voltmeter mecha- Screw driver, 
nism in case. 

Insert voltmeter mechanism in its case so that the pointer adjust- 
ment screw arm on the face of the case meshes in the adjusting fork 
on the instrument. Put in three screws attaching case to instru- 
ment and tighten. 

/. Installation of assembly. — Tools : 

ii/32-irLch open-end wrench. Screw driver. 
%-inch open-end wrench. 

(1) Install voltmeter on instru- 1%2-iiich open-end wrench, 
ment panel. Screw driver. 

Place voltmeter in hole on instrument panel so that the dial is in/ 
the proper reading position. Slide retaining clamp ring on case 
and tighten clamping screAv. 

(2) Connect voltmeter to sys- %^inch open-end wrench, 
tern. 

Connect voltmeter wires to terminals and tighten terminal nuts. 

42. Speedometer (figs. 96 and 97). — a. Description. — The speed- 
ometer is of the centrifugal magnetic type with a di&l reading for 
to 80 mph and an odometer unit for season and trip mileage. 

(1) Construction. — The magnetic-type speedometer, mounted in a 
case, has a pointer and dial graduated to indicate to 80 mph. The 
odometer unit of this instrument indicates total mileage (up to 
99,999). Extending at the rear of the case is a boss, which con- 
tains the bearing and drive shaft, and the stem for resetting the 
trip mileage unit. The boss is internally threaded to take the flex- 
ible drive shaft fitting. Two studs are attached to the back of the 
case to mount the speedometer to the instrument panel. 

(2) Operation. — (a) The speedorrieter is actuated by a positive 
driven revolving magnet exerting a drag on a circular metal speed 
cup which acts as a field. The speedometer pointer is attached to 
the field cup shaft. The field cup revolves in relation to the speed 
of the magnet, which is driven by a flexible shaft drive through a 
pair of gears located in the transfer case. 

(&) The season odometer unit is driven from the magnet shaft by 
a series of worms and worm gears. The trip odometer is driven 
from the season odometer by a pair of spur gears. To reset the trip 
mileage to zero, push in the resetting stem and turn clockwise. 

204 



TM 9-1709 

CHASSIS AKD BODY FOR SCOTJT CAES M3A1 42 




RA re «2is 



Figure 96. — Speedometer assembly — front view. 




'RA fD'"6il4 



FiGUEE 97, — Speedometer assembly — rear view. 

205 



TM 9-1709 

42 

(3) Specificatifyns. 



ORDNAKCE MAmXENANCE 



Make 


Type 


Manufacturer's No. 


Ordnance No. 


White No. 


Stewart-Warner 


Centrifugal 


SW-585-AM 


B156135 


326390 



i. Removal of nssemhly. — Tools : 

Pliers. %-inch open-end wrench. 

Screw driver. 

(1) Eemove speedometer flex- Pliers, 
ible drive shaft connection. 

Detach speedometer drive .shaft SW-9500084 by breaking 
connection at speedometer head. 

(2) Remove lamp bi-acket. Screw driver. 

Remove one screw SW-12389 and shakepro(jf washer BEAXlE and 
(letacli bracket SW-G-74124. 

(3) Remove speedometei' and %-inch open-end wrench, 
mounting brackets. 

Remove two nuts SW-12372 and lock washers SW-5052 from 
mounting bracket studs. Then take brackets SW-74074 off mounting 
studs and lift out speedometer assembly SW-585-AM. 

c. Disassemhly of coviponenU. (fig. 98). — Tools: 

Screw driver. Small screw driver. 

Pliers. 

(1) Remove speedometer asscm- 
bly. 

See I) above. 

(2) Remove rolled bezel glass Screw driver, 
and gaskets. " Pliers. , 

Pry bezel SW-74067, loose with screw driver in two places about 
1/2 inch apart, grab with pliers and tear section out (fig. 99©) . Pull 
bezel off. Remove glass SW-74070 and two gaskets SW-74072. 

(3) Remove pointer. None. 

Turn pointer SW-G-7759 to the right as far as it will go. Hold 
pointer at axis, twist to the right, and cai-efuUy pull off pointer 
(fig. 99@). 



206 



TM 9-1709 

CHASSIS A3VD BODY FOB SOOUT CARS M3A1 42 








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t SW-10 


Dial SW-984 
Screw SW-9 
Pointer SW- 
Bezel SW-74 


Brae 
Case 
Shat 


<^' ri d ft H ri d 



207 



TM 9-1709 

42 OKDNANCE MAINTENANCE 

(4) Eemove dial. Small screw driver. 
Eemove two screws SW-95051 and lift off dial SW-98470. 

(5) Remove odometer as- 
sembly. Screw driver. 

Remove three odometer frame screws SW-64796 and lift out odom- 
eter assembly (fig. 99(3)). 

(6) Remove field plate 

with bracket assembly. Screw driver. 

Eemove three screws SW-18035, holding field plate bracket to 
frame and lift out assembly (fig. 990) . 

(7) Remove speed-unit as- 
sembly with mounting frame. Screw driver. 

Remove two screws SW-13395 and lock washers SW-5052 from 
back of case and lift out speed-unit assembly (fig. 990) . 

d. Maintenance and adjustments. — (1) If speedometer is not reg- 
istering the speed of the vehicle and the miles of travel, inspect 
flexible drive conduit. If found to be hot, internal friction is de- 
veloping due to lack of lubrication or misadjustment. If a slight 
click Or thump can be heard, remove speedometer cable and inspect 
for distortion, incorrect length or diameter, or for breaks and worn 
connections. A defective cable should be replaced. 

(2) Remove cable conduit. Lubricate sparingly with grease, gen- 
eral purpose, seasonal grade, and reassemble. 

(3) If speed unit is out of order, replace speed-unit assembly and 
bracket. 

(4) If the odometer fails to register, replace odometer unit as- 
sembly and bracket. 

(5) Inspect dial pointer ; if loose on shaft, replace pointer. 

(6) Replace broken dial glass with new glass and bezel; and be- 
fore replacing, inspect mechanism for dust and dirt. If necessary, 
disassemble and clean parts thoroughly. 

e. Reassembly (fig. 98). 

(1) Replace field plate with 

bracket assembly. Screw driver. 

Place field plate bracket on frame. Insert three screws and 
tighten. 

(2) Replace odometer assem- 
bly on speed-unit frame. Screw driver. 



208 



Till 9-1709 

CHASSIS AND BODY FOK SCOUT CAES M3A1 42 





® Ikv.ol ro v;il. 



(D Xoedle reinovul. 




® Odouieter removal. 



® Speed unit removal. 




® Case removal. ® Bezel replacement with special tool S\V-X88I)T2. 

Figure 9!). — Speedometer disassembly, 



477229°— 42 14 



209 



TM 9-1709 

42-43 OKDlSrANCE MArNTEK'AKiCE 

Place odometer assembly on speed-unit frame, meshing cross drive 
shaft worm with odometer gear. Insert three screws and tighten. 

(3) Replace speedometer Screwdriver, 
mechanism in case. 

Place speedometer in case, lining up the trip reset stem with the 
hole in rear of case. Replace lock washers and screws and tighten. 

(4) Replace dial. Screw driver. 

Place dial on odometer frame so that the long slot in the dial is 
in line with the season mileage unit. Insert dial screws and 
tighten. 

(5) Replace dial pointer. None. 

Start pointer on shaft at about the 30-mile mark. Press it on 
as it is turned counterclockwise to zero. 

(6) Replace glass and bezel. Bezel rolling tool SW-T88972. 

Place new bezel, glass, and gasket in lower half of tool, face down, 
and place upper half of tool on lowei' half. Screw on tool stud 
nuts and tighten each nut a little at a time, to exert even pressure 
on bezel. After nuts are clown tight, remove (fig. 99®). 

/. histaUatA.on. 

(Ij Install speedometer on in- %-inch open-end wrench, 
strument panel. 

Place speedometer in hole on instrument panel. Slide bracket on 
moimting studs. Put on two lock washers and stud nuts. Hold- 
ing brackets in place, tighten nuts. Connect speedometer flexible 
(.Irive to speedometer fitting and tighten. 

(2) Install lamp bracket and Screw driver, 
socket assembly. 

Place lamp brsicket on reai' of speedometer ca.se in line with the 
screw hole. Insert screw and tighten. 

Secttoi^^ XI 
. SPRINGS AND SHOCK ABSORBERS 

Paragraph 

Front springs 43 

Rear springs ._! 44 

Shock absorbers 45 

43. Front springs. — a. Description. — The front springs are semi- 
elliptical, twin-back type. 

210 



TM 9-1709 

CHASSIS AND BODY FOR SOOUT CARS M3A1 43 

(1) Consii^ction (Hgs. 100 and 101) . — (a) Each spring is attached 
to the frame by means of an anchor and pin at the front end and a 
shackle and pins at the rear. They are attached at the center to the 
axle seat by means of U-bolts and nuts which also hold the bumper 
plates to the top of the springs. The front springs are mounted 
above the axle. 




\. Bracket, Wl-344004. 
!. Fitting, CLDXOA. 
:. Pin, WI-55900. 

fBoIt, Wl-A146inx. 
). } Nut, BBBXID. 

[washer, loclt, BECXIL. 

0. Nut, DR-14500fl. 

, fJMug (screw), Dll(i4ri:;75. 
'• jciasket, DR-04.5228. 

1. Screw, cap. B('BX2AN. 



■ a* l>B_7SSS 

.r. rnstrunient, w/lever, assembly DK- 

33423C8. 
K. Block, WI-32138S, 
L. Screw, BCXIKB. 
"Si. Spacer, \VI-344905. 
A'. Clip (U-bolt), WI-344!)7!». 
I'. Bi-ackrt assembly, Wl-311962. 
Q. Shackle, WI-55noi. ' 
S. Bracket, DR-5304693. 
X. Link, a.ssembly, 0352238. 
Y. Spring assembly, EAT-32."i41. 



FiciUiiE 100. — Front spring and shock absorber, installed. 

{b) To prevent breakage at the ends of the spring, it is necessary 
to wrap both the first and second leaves around the bushings at the 
eyes. To permit movement of the first and second leaves as they 
bend and still maintain a tight strong wrap, the second leaf is made 
in three pieces. At the center is an H -shaped section, slightly thicker 
than the two other sections of the second leaf. Into the recesses 
formed by the H, the tang-ends of the end sections are allowed to 
slide. The joint formed between the center section and the two end 



211 



TM 9-1709 

43 



ORDNANCE MAINTENANCE 



sections of the second leaf often gives the false impression of a broken 
spring leaf, and may lead to complaints. A thin wear plate is in- 
serted between the H -section of the second leaf and the top leaf. 
The leaves are bolted together at the center and held by four clips 
along the length, two clips between the center and each end. 

(2) Functioning. — The springs flex with every movement of the 
wheels and prevent the frame from taking the jolts. The second 
wrapper leaf is divided as explained above; the end sections slip 



PLATE - Wl - 375551 

LEAF NO. 1 

FRONT.FIXED 

CLIP -EAT -1 -2876 

RIVET -EAT -6 -1205 

CLIP - EAT - I - 2888 

RIVET -EAT -6 -1205 




BOLT - Wl - AI0381X 

SPACER(TUBE) - EAT - 5 - 158 

NUT-BBAXIA 

BUSHING -EAT- 4- 5221 

BOLT - EAT - 2N3672 

NUT -EAT -3- 12 

PLATE -EAT -7- 1291 



SPRING.FRONT, ASST - 



EATON MFG. CO.- 32541 
WHITE MOTOR CO.- 344977 
ORDNANCE NO - BI67748 



LEAF NO.l 



CLIP -EAT -1-1811 

RIVET -EAT -6-I208J 

CLIP -EAT -1-1835" 

RIVET - EAT - 6 - 1208 




BOLT -EAT - 2-1005 

SPACER(TUBE) - EAT - 5 - 124 

NUT-BBAXIC 

BUSHING -EAT- 4-5162 

BOLT - EAT - 2N3673 
NUT -EAT - 5-12 



EATON MFG. CO.- 32546 

SPRING, REAR, ASS'Y j WHITE MOTOR CO.- 344976 

JJRDNANCE NO. - BI67747 
Figure 101. — Spring assemblies — sectionalized view. 



RA FSO I874C 



back and forth with each flexing of the springs, and thus prevent 
excessive breaking of levers. When the wheels drop into a deep hole 
or hit a sharp bump, the shock absorbers may not be able to take 
the entire jolt, and the springs will flex until the bumpers on top of 
the springs hit the bottom of the frame, thus preventing further 
flexing of the springs which might break them. 
(3) Specifications. 



Make 


Type 


Manufacturer's No. 


Ordnance No. 


White No. 


Eaton Manufactur- 
ing Co. 


Twin-back 


EAT-32541 


B167748 


344977 



212 



Tin 9-1709 

CHASSIS AND BODY FOB SOOUT CARS M3A1 43 

Front spring : 

Center to center of eye 37 in. 

Center of eye to seat center 18 in. 

Width 214 in. 

Kebound clips 4 

Leaves : 

Quantity — 9 (plus one top I'ebound plate) 

Thickness 3 leaves 0.29 in.; 6 leaves 0.262 in. 

Rebound plate 0.262 in. 

H-plate thickness 0.323 in. 

Wear plate thickness 0.031 in. 

Total thickness of spring 2.847 in. 

5. Trouble shooting. 

Symptom and probable cause Probable remedy 

(1) Hard riding. 

Insufficient lubrication. Lubricate shackle pins. 

Broken shackle pins. Replace with new pins. 

Overloading or uneven load Redistribute load. 
. distribution.' 

(2) Over flexibility. 

Broken spring leaves. Replace broken leaves. 

c. Removal of assembly {fig. 101). — Tools: 
Hydraulic jack. Brass drift. 

i%g-inch open-end wrench. Hammer. 
i%6"inch socket wrench. Pliers. 

(1) Jack up vehicle. Hydraulic jack. 

Place jack under frame just back of spring to be removed. Raise 
jack until all load is removed from spring. 

(2) Remove U-bolts (clips). i%e-inch socket wrench. 

Take otf U-bolt nuts WI-A6I0IX and lock washers BECXIP and 
remove clips WI-344979 and spacer assembly WI-344978. 

(3) Remove spring assembly. i^g-inch open-end wrench. 

Brass drift. 

Hammer. 

Pliers. 

Pull out shackle pin cotter pins BFA-lCC and remove nuts WI- 
A8371X. Drive shackle pins WI-o5900 out of front bracket WI- 
344904 and rear shackle WI-5o901 and lower spring assembly EAT- 
32541. 



213 



TM 9-1709 

43 OEDIviANCE MAINTENANiCE 

d. Disassembly. — -Tools: 

Drift. i%g-inch open-end wrench. 

Hammer. Brass drift. 

5/g-inch socket wrench. Cold chisel. 

■ %g-inch open-end wrench. PUers. 

(1) Eemove spring from ve- 
hicle. 

Follow steps outlined in r;(l), (2), and (3) above. 

(2) Remove spring eye bushings. Drift. 

Hammer. 

Drive bushings EAT-45221 out of spring eyes at ends of spring. 

(3) Disassembly spring leaves. %-inch socket wrench. 

%g-inch open-end wrench. 

Hammer. 

Drift. 

Remove spring clip nuts BBAXlC, bolts WI-A10381X, and spacers 
EAT-5-158. Then remove center bolt EAT-2N-3672 and nut 
BBBXIC and separate leaves. Drive .second wrapper leaf off first 
wrapper at eyes with a hammer and drift. The two small clips 
EAT-1-2876 a]id two large clips EAT-1-2888 come away with the 
leaves to which they are riveted. 

(4) Separate clips from leaves. Hammer. 

Cold chisel. 

If necessary to replace clips or the leaves to which they are riveted, 
cut rivets EAT-6-120.5 holding clips EAT-1-2876 and clips EAT-1- 
2888 to leaves WI-375545 and WI-375549 and remove clips. 

(5) Remove rear shackle from i5.^(;-inch open-end wrench, 
frame. Brass drift. 

Hammer. 
Pliers. 

Pull out shackle pin cotter pin and remove nut. Drive shackle pin 
out of shackle at frame and lower shackle. 

e. Maintenance and adjustments. — (1) Check the U-bolts (clips) for 
breakage and their nuts for tightness; the nuts should be tightened 
periodically. Loose U-bolts permit the leaves to shift, thus shear- 
ing the center bolt. Consequently, niisalinement of the axle with 
the frame occurs. This causes broken leaves and impro]3er wheel 
alinenient. 



214 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 43 

(2) Inspect spring eye bushings for wear and replace any which 
are oversize beyond the allowable tolerance (see (5) below). 

(3) Check shackle pins for wear, breakage, and plugged lubrica- 
tion passages. Replace broken or excessively worn pins and clean 
out any plugged lubrication passage. 

(4) Inspect the rubber bumpers for indications of excessive bump- 
ing. If any is evident or if the bumpers are missing, check for 
broken leaves or leaves which have taken a permanent set. These 
should be replaced with new leaves. 

(5) SerA'ice data. 

Spring bushings (bronze) 0.003 in. 

Inside diameter ^ 1 in.-0.005 in. 

/. Reassembly. — Tools : 

3%6"irich open-end wrench. Riveting hammer. 

^'](5-inch open-end wrench. Press. 

Pliers. %-inch socket wrench. 

Hamniei'. i%g-inch open-end M'rench. 

(1) Replace shackle. Pliers. 

Hammer. 

Hold shackle in position and replace shackle pin. Replace shackle 
pin nut and cotter pin. 

(2) Attach clips to their re- Riveting hammer, 
spective leaves. 

Rivet c]i]5s to leaves and smooth down inner ends of rivets. 

(3) Tie leaves together. Press. 

%-inch socket wrench. 
%6-inch open-end wrench. 

Press second wrapper leaf eyes onto first wrapper leaf. Stack 
leaves together in their correct order and replace center bolt and nut. 
Replace bolts, spacers, and nuts in clips along length of spring and 
lighten entire assembly. 

(4) Replace bushings. Press. 
Press bushings into spring eyes. 

g. Installation of assembly. — Tools: 

^%6-inch open-end wrench. ^^g-inch socket wrench. 

Pliers. 1%6-inch open-end Avrench. 

Hammer. Pliers. 

(1) Attach spring assembly to Hammer, 
frame. 

216 



TM 9-1709 

43-44 



ORDNIANCE MAINTENANCE 



Hold spring in position and tap shackle pins into shackle and 
bracket. Turn shackle pin nuts up tight and then back them off 
one-half turn to prevent any binding. E-eplaee cotter pins in shackle 
pins. Always use new cotter pins for replacing. 

(2) Attach spring to axle as- i%e-inch socket wrench, 
sembly. 

Set spacer assembly on top center of spring straddle spacer and 
spring with U -bolts (clips) which then pass down through holes in 



.i.'^;;'-? 




A. Spring assembly l':AT-32546. 
/Nut BBBXIC. 
J^ Washer, lock, BECX3K. 

C. Screw, cap, BCBXICG. 

D. Nut BBIIX2A. 

B. Fitting CLDX5A. 
K. Pin WI-00848. 

G. Sliackle assembly (left-hand) 
U. Bracket WI-81 1007. 

r Screw, cap, BCBXICK. 
J.J Nut BBBXIC. 

[Washer, lock, BECXlK. 



WI-83341. 



N 

P 

r I- 
■•.1=1'--. .4^' 

nth* 
i 

U T 

Same as J. 

Kod WI-44088. 

Nut BBBX2A. 

Link assembly DE-53.^2237. 

Clip (U-bolt) WI-62698. 

Clip WI-62972. 
K. Nut BBBXIE. 
S. Same as P. 
T. Plate WI-62699. 
V. Nut WI-Afil.51X. 
V. Washer, lock, BECXIP. 
W. Instrument DR-5342365. 



RA PD 7394 



FiODRK 102. — Bear spring and shock absorber, installed. 

projections on axle housing and shock absorber connecting link brac- 
ket. Keplace U-bolt lock washers and nuts and tighten down assembly. 

(3) Remove jack. None. 

Lower jack until weight of car rests on spring then pull out jack. 
44. Rear springs. — a. Description. — The rear springs are semi- 
elliptical, leaf type. 



216 



TM 9-1709 

CHASSIS AND BODY FOiR SCOUT CARS M3A1 44 

(1) Gonstrucfion (figs. 101 and 102).— (a) Each spring is attached 
to the frame by means of a bracket and pin at the front end and a 
shackle and pin at the rear. The springs are below the axle and are 
fixed at the center to the axle seats by means of U-bolts and nuts. The 
brackets are attached directly to the frame and the shackles are 
bronze bushed and hang from the frame cross rod. 

(h) To prevent breakage at the ends of the spring, it is necessary 
to wrap both the first and second leaves around the bushings at tlie 
eyes. The second leaf is tapered and thinned somewhat at its extrem- 
ities, so that ends may yield a little as the springs are compressed 
and the first leaf approaches a straighter position. The leaves arc 
bolted together at the center and held by four clips along the length, 
two clips between the center and each end. 

(2) Functioning. — The springs flex with every movement of the 
wheels and prevent the frame from taking the jolts. The second leaf 
may give a little at its ends with each flexing of the springs, as ex- 
plained above, and this reduces the risk of breakage. When the 
wheels drop into a deep hole or hit a sharp hump in the terrain the 
springs take any portion of the jolt that is too much for the shock 
absorbers. The use of the Hotchkiss drive, by which the vehicle is 
propelled directly through the springs, eliminates radius rods and all 
component parts. 

(3) Speciflcaiions. 



Make Type I Manufacturer's No. Ordnance No. White No. 



Eaton Maiuifacturing Semi-elliptical EAT-32546 | B167747 : 344976 

Co. , j j i 

Rear spring: 

Center to center of eye 54 in. 

Center of eye to seat center 27 in. 

Width - 21/2 in. 

Rebound clips 4 

Leaves : 

Quantity 10 

Thickness of each 0.375 in. 

Total thickness of spring 3.750 in. 



217 



TM 9-1709 

44 



ORDlsrANCB MAINTENANCE 



6. Trouble shooting. 
Symptom and prohable cause 

(1) Hard riding. 
Insufficient lubrication. 
Broken shackle pins. 
Overloading or u neve n 

load distribution. 

(2) Over flexibility. 
Broken spi'ing leaves. 

c. Retnoval of assevibly. — Tools : 

Hydraulic jack. 
i%g-inch socket wrench. 

%6- 



Prohable remedy 

Lubricate shackle pins. 
Replace with new pins. 
Redistribute load. 



Replace broken leaves. 

Chisel. 
Hammer. 
Brass drift. 



Hydraulic jack. 



-inch socket Avrench. 
^e-ii^ch open-end wrench. 

(1) Jack up vehicle. 

Place jack under frame just back of spring to be removed. Raise 
jack until all load is removed from spring. 

(2) Remove U-bolts (clips). ^yig-inch socket wrench. 

Take off four U-bolt nuts WT-A6151X and lock washers BECXIP. 
Then remove clip plate WI-62699 and bolts WI-62698. 



(3) Remove spring assembly. 



%6"ii^ch open-end wrench. 

%6"iJich socket wrench. 

Chisel. 

Hammer. 

Brass drift. 

Remove three nuts BBBXlC, lock washers BECXlK and cap 
screws BCBXlCG. clamping shackle pins WI-55848 in shackle 
assembly WI-333411 (left-hand), WI-333410 (right-hand), and 
front bracket WI^4081. Loosen pins in shackle and bracket by 
forcing chisel into split and then drive out pins. Lower spring 
assembly EAT-32546 to floor. 



d. Disassembly. — Tools : 

Drift. 
Hammer. 

%-inch socket wrench. 
(1) Remove spring from vehicle. 

Follow steps outlined in c(l), (2), and (3) above. 



%6-iiich open-end wrench. 
Brass drift. 
Cold chisel. 



218 



Tlffi 9-1709 

CHASSIS AND BODY FOE SCOXJT CARS M3A1 44 

(2 ) Eemove spi'ing eye bushings. Drift. 

Hammer. 

Drive two bushings EAT-4-5162 out of spring eyes at ends. 

(3) Disassemble spring leaves. %-inch socket wrench. 

%6-inch open-end wrench. 

Hammer. 

Brass drift. 

Eemove four nuts BBAXlC, spring clip bolts EAT-2-1005 and 
spacers EAT-5-124. Eemove center bolt EAT-2N-3673 and nut 
BBBXlC and separate leaves. Drive second wrapper leaf off of first 
wrapper at eyes with hammer and drift. The two small clips 
EAT-1-1811 and two large clips EAT-1-1835 come away with the 
leaves to which they are riveted. 

(4) Separate clips from leaves. Hammer. 

Cold chisel. 

If necessary to replace clips or the leaves to which they are riveted, 
cut rivets BCMXl holding clips EAT-1-1811 and EAT-1-1835 to 
leaves WI-375531 and "^1-375635 and remove clips. 

e. Maintenance and adjustments. — (1) Check the U-bolts (clips) 
for breakage and their nuts for tightness. The nuts should be 
tightened periodically. Loose U-bolts cause the leaves to shift and 
shear the center bolt. Consequently misalinement of the axle with 
the frame occurs, and this results in broken leaves and improper 
wheel alinement. 

(2) Inspect spring eye bushings for wear and replace any which 
do not fit the pins snugly (see (4) below). 

(3) Check shackle pins for weai', breakage, and plugged lubri- 
cation passages. Eeplace broken or excessively worn pins and clean 
out any plugged lubrication passage. 

(4) Service data. 

Spring bushings (bronze) 0.003 in. 

Inside diameter ^Vie in.-.O05 in. 

/. Reassembly. — Tools: 

Eiveting hammer. %-inch socket wrench. 

Press. % 6-inch open-end wrench. 

(1) Attach clips to their re- Eiveting hammer, 
spective leaves. 

Eivet clips to leaves and smooth down inner ends of rivets. 



219 



TM 9-1709 

44-45 ORDNAKCE MA,1XTENANCE 

(2) Tie leaves together. Press. 

%-inch socket wrench. 
%e"iiich open -end wrench. 

Press second, wrapper leaf eyes onto first wrapper leaf. Stack 
leaves together in their correct order and replace center bolt and 
nut. Replace bolts, spacers, and nuts in clips along length of spring 
and tighten entire assembly. 

(3) Replace bushings. Press. 

Press bushings into spring eyes. 
g. Installation, of assembly. — Tools : 

%6-irich open-end wrench. '•'^^e-inch socket wrench, 

^ig-inch socket wrench. Hammer. 

(1) Attach spring assembly to %6'iiich open-end wrench, 
frame. %6-iiich socket wrench. 

Hammer. 

Hold spring in position and tap pins into shackle and bracket. 
Replace cap screws, lock washers, and nuts, clamping piiis in place. 

(2) Attach spring to axle as- ^^g-inch socket wrench, 
sembly. 

Straddle axle housing with U-bolts (clips) at each side of spring. 
Set plate onto bolts at bottom of spring and fasten assembly with 
lock washers and U-bolt nuts. 

(3) RemoA^e jack. None. 

Lower jack until weight of car rests on spring and then pull out 
jack. 

45. Shock absorbers. — a. Descriftion. — The shock absorbers are 
of the double acting type. They control the compression and the 
speed of rebound of the front and rear springs. 

(1) Construction (figs. 103 and 104). — (a) The shock absorber 
unit consists of a cast steel housing which incloses the operating 
mechanisms. The housing is separated into a reservoir section on 
top and a cylindrical piston chamber below the reservoir. The pis- 
ton is inclosed by a cap, threaded into each end of the chamber and 
is actuated by a cam fastened to and actuated by the operating lever 
arm shaft. An antirotation spring prevents the piston from turning 
within the cylinder. 

A spring-loaded valve is fixed into each end of the piston by a 
retainer clip and controls the flow of fluid from the reservoir to the 



220 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CAES MSAl 45 







COMPRESSION 
END 



A. Piston screw expansion plug. 

B. Piston. 

C. Piston screw spring. 

D. Piston screw. 

E. Antirotatlon spring. 
V. Cam button. 

G. Cam. 

H. Fluid reservoir. 

I. Filler plug. 

J. Compression end of shock absorber. 

K. End cap. 

L. Rebound valve nut. 



RA PD 9831 

COMPRESSION 

REBOUND 

M. Rebound valve spring. 

N. Rebound valve. 

0. Compression valve. 

P. Compression valve spring. 

Q. Compression valVe nut. 

R. Rebound end of shock absorber. 

S. Valve spring retainer clip. 

T. Intake valve spring, rebound end (sim- 
ilar spring on compression end). 

U. Intake valve, rebound end (similar 
valve on compression end). 



Figure 103. — Shock absorbers — sectlonallzed view. 



221 



TM 9-1709 

45 



OEDiNIAlSrCE MAINTEOSTANCE 



>^1 



•a ^3 
c a 

3 



o at 

PS ss 



M 3 


■^ 
















a t4 




7J 






(IJ 






t<' ^ 


:q 


a; 






«H "^ 




(D Oi 




.PH j;5 








"3 a; 




;h 'h 




a c 




_o 3 








'sc '» 


di 


m m 


cS 


9 P 


o 


"^ Q4 


-c 


S C 




o o 


^ 


w :-J 



<i »■ d Q 



222 



TM 9-1709 

CHASSIS AKD BODY FOR SCOUT CARS M3A1 45 

space between the ends of the piston and cylinder. The casting be- 
low the cylinder has two passages drilled into it which interconnect 
the compression and rebound ends of the cylinder ; one passage is in 
use during comj^ression and the other during rebound. Each passage 
contains a spring-loaded A'alve, held in place by nuts, for control- 
ling the flow of fluid between the cylinder ends. Each valve has a 
small orifice to take care of the fluid flow during small, slow move- 
ments of the lever arm. 

(h) The unit is bolted to the vehicle frame above the springs, the 
upper end of each connecting link being held to the piston operating 
arm by a special bolt and nut (figs. 100 and 102). The lower ends 
of the front shock absor-bei' connecting links ai'e attached to the spring 
U-bolt clips at the bottom of the front axle spring seats by means 
of a bracket, and the rear connecting links ai'e attached, by means of 
brackets, to clips fastened to the rear axle. The instrument filler' plug 
screws into a thre.ided hole located in the upper lever arm end of the 
housing. 

(2) Functioning. — {a) The flow of fluid is shown in figure 103. As 
the arm moves upAvard (compi'ession stroke), the piston moves to- 
ward the ai-m or compression end of the shock absorber, thereby dis- 
placing the fluid in this end. In very slight or slow axle movements, 
the fluid flows only through the orifice of the compression valve and 
into the rebound end of the shock absorber cjdinder. In rapid move- 
ments, the pressure lifts the valve from its seat by compressing the 
valve spring, thus letting a greater volume of fluid into the rebound 
end. At the same time, the intake valve at the rebound end of the 
piston opens, allowing fluid to flow from the reservoir into the re- 
bound end of the cylinder. This is to compensate for any loss of 
fluid between piston and cyliiider walls from the compression end into 
the reservoir. 

{h) As the arm moves downward (rebound stroke) the direction of 
flow is reversed, the rebound valve opens, and the intake valve in the 
compression end of the piston opens. 

(3) Specifieafions: 



Make 



Delco Products. 



Type 



Double acting.. 



MaTinfner.urer's Mo. 



I)R-634236» right front. 
r>R-5342368 left front.. 
DE-6342364 right rear. 
DB-5342365 left rear.... 



Ordnance No. 



White No. 



A)80886 front. .. . ' 363760 right front. 
363759 left front. 
363450 right rear. 
363449 left rear. 



A190887rear-- 



223 



TM 9-1709 

45 



ORDNANCE MAINTEKANCE 



&. Trovhle shooting. 

Sijmptom and proliahle cause 

(1) Overflexibility. 
Lack of fluid in shock ab- 
sorbers. 

Damaged or worn internal 
parts. 

(2) Leakage. 
Operating shaft packing 

worn or damaged. 

Defective casting. 

Gaskets at valve nxits or 
end caps worn or dam- 
aged. 

c. Rem,oval of assenthly. — Tools: 

34-inch socket wrench, 
i-yig-inch socket wrench. 

(1) Disconnect link from 
bracket. 

Remove nut DR-145009 and drive out the bolt holding lower end 
of connecting link to bracket WI-363758 (front left-hand), WI-6a970 
(rear left-hand), WI-62971 (rear right-hand). 

(2) Remove instrument assem- i^g-inch open-end wrench, 
bly from frame. i%e-inch socket wrench. 

Remove two nuts BBBX2A, lock washers BECXIN and screws 
BCBX2AN, holding each assembly to frame and lower assembly. 

d. Disassembly (fig. 106). — Tools: 

%-inch socket wrench. Screw driver. 

Soft metal hammer. Heavy duty screw driver. 

Special holding fixture and Sharp punch. 



ProT)able remedy 

Refill reservoirs with Delco 

fluid. 
Replace parts, if possible, or 

replace unit. 

Replace instrument assembly. 

Replace instrument assembly. 
Replace gaskets. 



Soft metal hammer. 
1%6-inch open-end wrench. 
34-inch socket wrench. 
Soft metal hammer. 



wrench. 
(1) Disconnect link from in- 
strument arm. 



Hammer. 

%-inch socket wrench. 

Soft metal hammer. 



Remove nnt DR-145()09 and drive out bolt holding link to instru- 
ment arm. 



(2) Remove end caps. 



and 



Special holding fixture 
wrench. 
Place shock absorber in assembly fixture (fig. 105). Do not clamp 
instrument in vise. Then, using a special wrench (fig. 106), remove 
end caps DR-043215 and gaskets WI-37385T. 

224 



TM 9-1709 

CHASStrS AWD BODY FOB SOOXJT CARS M3A1 45 



(3) Remove intake valves. 



Screw driver. 



Pry out spring retainers WI-373860 with screw driver and lift out 
valves WI-373858. 

(4) Remove compression and Heavy duty screw d river, 
rebound valves. 








RA PD 9852 

Fiorui-: lO."!. — Shock alisorboi" (lisiiyweiiibly tixfiirp. 

Remove valve nuts DR-043233 and gaskets WI-373862 and lift out 
compression valves WI-375685 and rebound valves WI-373882 (front 
shocks), WI-373881 (rear shocks) (fig. 107). 

(5) Disassemble piston. ScrcAv driver. 

Sharp punch. 
Hammer. 



722n° — 42- 



225 



TM 9-1709 

45 



O'RDA^AXCE MAIXTE^-'ANCE 




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226 



TM 9-1709 

CHASSIS AND BODY FOE SOOUT CARS M3A1 45 







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227 



TM 9-1709 

45 



OKDNIAKCB MAINTENANCE 




ffi 




FiGURB 107. — Compression and rebound valve repioval. 



228 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 45 

Kemove plugs DE-046810 over piston screws by piercing with 
punch and lifting out. Then remove piston screws "RT-373888 and 
springs WI-373889 and disassemble piston DK-5316451. 
Note. — The instrument assemblies cannot be disassembled beyond this point. 

e. Maintenance and adjustments. — (1) Check connecting link, 
studs, and bushings for wear and damage and if any is evident, 
replace with new parts. 

(2) Remove shock absorbers from the vehicle, flush out com- 
pletely, overhaul and refill every 50,000 miles. 

(a) After disassembly, wash shock absorber and all parts in 
kerosene and inspect for wear or defects. Blow out valve orifices 
with compressed air and make certain valves are clean. 

(5) Check camshaft for wear in housing by moving shock arm 
sideways. If shaft is galled or worn, replace complete unit. 

(8) Check shock absorbers, without removing fi'om the vehicle, 
every 10,000 miles to be certain that they contain sufficient fluid. 
If necessary, refill them as follows: 

{a) Disconnect link at lower end. 

(6) Thoroughly clean the instrument around the filler plug and 
then remove plug. An ordinary paint brush, dipped in solvent, dry- 
cleaning, will remove most of the dirt, then use compressed air or 
a clean cloth to remove any remaining small particles of dirt. 

(c) Use a fluid gun and refill units to capacity with light shock 
absorber fluid only. Work arm slowly up and down while adding 
fluid. When the instrument is properly filled, there will be uniform 
resistance and no rubbery feeling or lost motion. 

{d) Eeplace the filler plug, using new gasket if necessary. Con- 
nect the link assembly. 

(4) Compression and rebound valves of proper spring strengtli 
and orifice size are selected for the particular vehicle by the manu- 
facturer to give the best possible ride under practically every riding 
condition. There should be no necessity for making valve changes 
unless extraordinary road or load conditions are met. In such cases 
valves for heavier or lighter resistance are available for replacement. 

(5) To check for leaks fill the unit, clean the exterior with solvent, 
dry-cleaning, and blow dry with air. Drive over rough ground and 
then inspect the unit carefully. 

{a) Note the condition around the shaft at the arm packings and 
also at the cover plates, valve nuts, and cylinder end caps. A slight 
leak at the arm packings around the shaft is of little consequence 
with a newly filled shock absorber : it is due to the initial expansion 
after filling. A severe leak at the arm packings around the shaft 

229 



TM 9-1709 

45 ORDN)AT<CE m:ainte;nance 

is serious and the unit must be replaced, as these packings are impos- 
sible to service. If the insti-unient is leaking at any of the above- 
mentioned places, except the arm paclvings, install new gaskets. 

(h) A leak at some part of the body denotes a defective casting 
and cannot be repaired. If this condition is found, replace the unit. 
/. Reassemhly. — Tools : 

Screw driver. Special retainei- replacing tool. 

Special holding fixture. Heavy duty scrcAv driver. 

Drift. Special end cap wrench. 

Hammer. %-inch socket wrench. 

(1) Reassemble piston. Screw driver. 

Special holding fixture. 

Attach instrument housing to special fixture and then assemble 
piston with cam clearance up, and also with high arm of antirotation 
spring up. Replace ]:)iston screws and springs. Turn screws down 
tightly and then back off about one to one and one-half turns to 
pi'event a bind between cam and cam buttons. 

(2) Install new piston screw Drift, 
plugs. Hammer. 

Install new plugs over piston screws and expand in place. 

(3) Replace intake valves. Special retainei- replacing tool. 

Hammer. 

Insert valves and replace valve spring retainers, using special tool 
(fig. 108). 

(4) Replace compression and Heavy duty screw driver, 
rebound valves. 

Insert valves and fasten in place with valve nuts. Use new gaskets 
under nuts. 

(5) Replace end caps and refill Special end cap wrench, 
instrument. 

Replace one end cap, using new gasket, and rotate fixture until 
open-end of instrument is up. Fill shock to capacity with new light 
shock absorber fluid. Wliile filling, move shock arm through com- 
plete strokes to expel the air from the fluid. Replace other end cap 
and rotate fixture until shock absorber is in its normal operating 
position on vehicle. Remove filler plug and allow fluid to drain 
down to the level of the filler plug hole. This is to allow air space 
at the top of the instrument reservoir for the natural expansion of 
the fluid. Replace filler plug, using new gasket. 

230 



TM 9-1709 

CHASSIS AKD BODY FOB SOOUT CARS M3A1 45 

(6) Attach link to instrument %-inch socket wrench, 
arm. Hammer. 

Tap link bolt through link and arm and rejilace holding nut. 
Take care in replacing bolt that rubber bushing is not damaged. 




PD 9S34 



Kii;ui£i-: Hi^. Shock ;il>si)rl>er jiituK'e valve replacement. 



g. InntaUatiun of assembly. — Tools : 

1%^-inch open-end wrench. y^Awh socket wrench. 
1%^-inch socket wrench. Hammer. 

(1) Attach instrument to ' i%e-inch open-end wrench, 
frame. i^e-inch socket wrench. 

Hold assembly in position and replace holding screws, lock washers 
and nuts. 



231 



TM 9-1709 

45-46 ORDNANCE MAINTENANCE 

(2) Attach connecting link to %-inch socket wrench, 
bracket. Hammer. 

Tap bolt through lower end of connecting link and bracket and 
replace holding nut. 

Section XII 

STEERING GEAR AND DRAG LINK 

Paragraph 

Description 46 

Trouble shooting , 47 

Removal of assembly 48 

Disassembly of components 49 

Maintenance and adjustments 50 

Reassembly of components 51 

Installation of assembly 52 

46. Description. — a. Construction. — (1) Steering gear (fig. 
109). — This is of the cam and lever design, twin-lever type. The 
cam is integrally welded to the steering wheel tube and is mounted 
between two ball bearings which are adjustable by means of shims 
between the housing and upper cover. The steering wheel tube is 
encased and supported by tlie outer jacket housing. The pitch of 
the cylindrical cam is not constant but is less at the center than it 
is at the ends, that is, the cam groove is cut at a smaller angle at the 
midway point between the ends than at the ends of the cam. This 
provides a variable gear ratio between the straight ahead driving 
position and turning or parking positions. The purpose of this con- 
struction is to obtain a larger gear reduction for the normal straight 
ahead positions, thereby reducing road shock, promoting easy steering, 
and preventing wander. The smaller gear reduction at the turning 
and parking range of the cam promotes quick and easy steering on 
turns. The cam groove is ground slightly higher in the normal 
straight ahead driving range to provide a closer adjustment of the 
clearance between the studs and cam at the point of steering action. 
Two studs, mounted on the lever shaft, engage the cam groove. The 
clearance between the cam and studs is adjustable by means of the 
screw and lock nut mounted on the housing side cover. The lever 
shaft is mounted in two steel backed babbitt bushings and the steer- 
ing arm is attached to the splined end of the lever shaft and secured 
by a nut and lock washer. An oil seal is provided on the shaft at 
the outer end. 

(2) Brag link (fig. 110). — This is of the tubular type, with adjust- 
able spring loaded ball sockets. At the axle end, the spring and spacer 



232 



TM 9-1709 

CHASSffS A3ST) BODY FOR SCOUT CARS M3A1 46 



PERMISSIBLE LASH IN PIN 
POSITIONS (A) & (81 
ON TURNS 




/Screw, Cap, BANXlBIi. 
■jWashei', lock, BECXUr. 
. Lever, .shaft, assembly RG-7569-0-1/2. 

fScrew EG-021065, 

\Nut, .iam, KG-025U8.I. 
, Cover ]!G-T205001 . 
. Vent. 

Tube, asseniblv KG -S-I4(! .:iS-l/4. 

fBolt BAOXIBG. 
■i Xut BBBXIB. 

[Washer BKCXIH. 



IL 

I. 
J. 
K. 
L. 

M 

N. 

0. 
I'. 



FiGUiiB 100.— Steering gear 



SHALLOWER GROVE AT lAl & 
"STRAIGHTAHEAO" POSITION 



RA.PD 702C 

f (.002) RG-0.H3042. 
ShiiiJ (.003) EG-0330;!C. 
[ (.010) RG-033037. 
Cover RG-T206000, 
Ping A17547(j. 

Housing, assembly RG-r)0;i:138. 
Cam w/tube. assemlily RG-7754-47 

-13/10. 
I*;ver shaft i)ins. 
Nut, jam, RG-EGIP. 
Washer, lock, BECX2T. 
Arm, assembly RG-502485. 
Bushing (outer) BG- 008003. 
— sectionalized view. 



233 



TM 9-1709 

46 ORDNANCE MAIKTENANCE 

are assembled between the ball seat and rod end (bottom of socket). 
At the steering geai- end the spring and spacer are beitween the ball 
seat and end plug, A leather boot is laced on to each end of the drag 
link to keep out dust and grime. 

h. Funotio'ning. — (1) Steenng gear. — ^Turning the steering tube by 
means of the steering wheel moves the tapered studs of the lever shaft 
through the cam on the groove, thus rotating the lever shaft and pro- 
viding angular movement of the steering arm. The two studs engage 
the cam for normal straight-ahead driving. The unit pressure on the 
studs and cam groove sides is therefore lower for this position where 
most of the steering action occurs. As the steering action moves into 
t-he parking range one of the studs disengages the cam (moves out of 
the end of the groove) and the other stud moves above the cam axis, 
tiiereby greatly increasing the elective leverage. 

(2) Drag link. — This is the connecting link between the steering 
gear and the steering arm on the front axle steering knuckle. It is 
connected to and receives its forward and backward motions from 
the lever shaft arm. These motions are transmitted to the steering 
ai-m, which rotates the steering knuckles, and this in turn causes the 
wheels to turn. 

c. Sfecifications. — (1) Steering gear. 

Make Ross Gear and Tool Co. 

Model Series T-26. 

Number T-27071. 

Type Cam and twin lever. 

Ordnance Xo E2140. 

White No 344926. 

Bearings : 

Cam Ball. 

Ball diameter % in. 

Number of balls 28. 

Lever shaft Bushings. 

Steering wheel : 

Diameter 18 in. 

(2) Drag link. 

Make Superior Universal Products. 

Type Spring loaded, tubular. 

Number SU-80P102. 

Ordnance No C74082. 

White No 347385,363757. 



234 



TIKC 9-1709 

CHASSIS AND BODY FOiR SCOUT CARS M3A1 46 




235 



TM 9-1709 




47 ORDNANCE MAINTENANCE 


47. Trouble shooting. 




Siimptoni and probable cause 


Probable remedy 


a. Shiirmiy. 




Tire or wheel out of bal- 


Test and balance. 


ance. 




Drag link adjustment loose. 


Readjust. 


Improper steering gear ad- 


Check and adjust. 


justment. 




Low or unequal tire infla- 


Check and inflate. 


tion. 




Improperly acting shock 


Adjust, repair or replace. 


absorbers. 




Weak or broken springs. 


Eeplace springs. 


Incorrect toe-in. 


Adjust. 


Worn lever shaft. 


Replace. 


Worn and scored steering 


Replace. 


gear housing bushings. 




Worn bearing in top end 


Replace bearing. 


of steering gear jacket 




tube. 




Upper end of wheel tube. 


Replace. 


worn. 




Drag link ball seats worn. 


Replace. 


h. Pull to one sid'e. 




Unequal camber. 


See section V. TM9-1706. 


Unequal caster. 


See section V, TM9-1706. 


Unequal tire inflation. 


Check. 


Dragging brake. 


Adju.st. 


Tight wheel bearing. 


Adjust. 


c. Wander or weaving. 




Insufficient or reversed 


See section V, TM9-1705. 


caster. 




Excessive tightness in 


Adjust. 


steering system. 




Loose steering linkage. 


Adjust drag link. 


Worn steering gear lever 


Replace or adjust. 


shaft studs. 




Excessive play in steering 


Adjust. 


gear. 




Fit of lever shaft in hous- 


Replace bushings. 


ing bushings too loose. 




Worn steering arm ball. 


Replace arm. 



236 



TM 9-1709 

CHASSIS AND BODY FOE SCOUT CARS M3A1 47-48 



d. Road shock. 

Steering linkage too tight. 
Misalined drag link. 
Excessive spring flexibility. 
Improperly acting shock 
absorber. 

e. Hard steering. 

Lack of lubrication. 

Excessive tightness in sys- 
tem. 

Unequal or reverse caster. 

Steering gear cam thread 
brinelled from heavy 
blows, chipped or scored. 

Ball races at ends of cam 
brinelled, pitted or worn. 

Lever shaft studs chipped 
oi' worn. 

/. Oil leaks. 

Worn oil seals. 



Adjust. 

Repair or replace. 
Tighten or replace. 
Adjust or replace. 



Lubricate tie rod yoke, steering 

gear, and drag link. 
Adjust. 

See section V, TM9-1705. 
Replace. 



Replace. 

Replace lever shaft. 

Replace. 



g. Procedure. — To locate the general source of trouble, whether 
in the front axle, wheels, or steering system, disconnect the drag 
link from the steering arm ball. If any difficulty is then had in spin- 
ning the steering wheel, or if end play of the steering gear cam and 
tube or lever shaft is found, the steering gear is at fault. However, 
check wheel alinenient. wheel bearing adjustment, steering knuckle 
adjustment, and tire inflation. 

48. Removal of assembly. — a. Drag link (fig. 110). — Tools: 

Pliers. 

Plug wrencli or large screw 
dr-iver. 

(1) Remove cotter pins. Pliers. 

Unlace drag link boots WI-324635, WI-324634:, and remove. Pull 
out cotter pin BFAXIDT at each end of drag link "WI-347385. 

(2) Remove assembly. Plug wrench or large screw 

driver. 

Loosen adjusting plugs SU-80PO6, slip link from front axle steer- 
ing arm ball TD-2910-B2, and from steering gear arm RG-502485. 



237 



TM 9-1709 

48 



OWDNANiCE MAIdVlTEN'ANCB 




I IS 

^ s5 b' 

a O ^1 

<i m Q 



238 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 48 



h. Steering gear (fig. 111). — Tools: 

Screw driver. Wheel puller. 

1%-inch socket wrench. 
%6"inch soclcet wrench. 
%-inch socket wrench. 
(1) Remove horn button (fig. 
112). 

Disconnect horn button cable terminal EG-032053 at bottom of 
steering gear housing RG-XT-262020. Depress button and rotate 
one-sixth turn. This permits removal of horn button EG-450029, 



Spring puUback pliers. 
%-inch open-end wrench. 

None. 



PLATE, ASS'Y - RG-454895 
WASHER - RG-029032 




BUTTON - RG-450029 



CUP - RG-029037 

SPRING- RG- 401081 
CAP . RG-02903 1 

EMBLEM- RG-033078 
FERRULE -RG-05 1036 



SCREW WOOD - BCRX2AB 



RA PD 3719A 



FiGUKE 112. — Horn button — sectionalized view. 



contact cup RG-029037, spring EG^01081, cap RG-029031, cable 
assembly EG-502484, and ferrule EG-051025. 

(2) Remove steering wheel nut. Screw driver. 

114-inch socket wrench. 

Take out three screws BCRX2AB holding horn button base plate 
and remove plate RG-484884:, contact spring RG-401082, washer 
RG-029032, and steering wheel nut RG-C-20. 



239 



TM 9-1709 
48 



OKDNANiCE MAIMTEK'ANCE 




Cam w/tube assembly K 

7704-47-13/16, 
Button EG-450029. 
Cup RG-029037. 
Spring RG-40108J. 
Washer 029032. 
Cable assembly RG-8300-55. 
Ferrule RG-051038. 
Plate assembly RG-454895. 
Spring RG-401082. 
Cap RG-029031. 
Nut RG-C-20. . 
Screw BCRX2AB. 
Wheel WI-36SO01. 
Lever shaft assembly BG- 

7569-8 1/2. 
Balls RG-400014. 
Ring RG-400005. 
Cup RG-400021. 



FiQOBE 113. — Steering gear — Exploded view. 



240 



TM 9-1709 

CHASSIS AJSTD BODY FOR SCOUT OARS M3A1 48 




A, Nut KG-E-61-J:'. 

B. Washer, lock, BECXIT. 
(\ Arm assembly EG-503229. 
n/Bolt BADXICC. 
'^l Washer, lock, BECXIK. 

f Cover RG-T266000. 
K J Bolt BAOXIBG. 
iNut BBBXIB. 
[Washer BECKIH. 
F. Tube assembly RG-8440-38- 
1/4. 
Housing assembly EG-503138, 
Bushing (inner) RG-0()8002. 
Bushing (outer) RG-268003. 
Plug A17547(). 
Cover w/tube, assembly RG- 

7859-12. 
Pad WI-62506. 
Clamp WI-A427S1. 

((.002) RG-033042. 
Shim^ (.003) RG-033036. 
[(.010) RG-033037. 
Cover RG-T26o001. 
Screw, cap, BANXIBD. 
Gasket RG-T269000. 
Screw, set, RG-021065. 
Seat RG-028104. 
Spring RG-401105. 
Bearing RG-06o996. 



RA PD 3260B A B C 

Figure 113. — Steering gear — exploded view — Continued. 



47T229°— 42 16 



241 



TM 9-1709 

48-49 OEDWANCE MALNTENANlCE 

(3) Remove steering wheel. Wheel puller. 

Set up the wheel puller and remove steering wheel WI-344931 or 
WI-368501. 

(4) Remove springs and U-bolt. Spring puUback pliers. 

%g-inch socket wrench. 

Release clutch puUback spring from hook waslier WI-A6227X on 
steering gear housing. Remove two nuts BBBXIB and lock washers 
BECXIH from U-bolt at instrument panel support WI-316216. Re- 
move U-bolt WI-316213. 

(5) Remove steering gear. %-inch socket wrench. 

34-inch open-end wrench. 

Remove cap stud nuts BBBX2A and lock washers BECXlH hold- 
ing frame bracket cap, and remove cap. Then take out cap screw 
BCBX2AD, lock washer BECXIN and nut BBBX2A holding steer- 
ing gear housing to frame bracket assembly WI-344951 and lower 
steering gear assembly to floor. 

49. Disassembly of components. 

a. Steering gear (fig. 113). — Tools: 

i/^-inch socket wrench. Light file. 

% g-inch socket wrench. Small puller, 

i/^-inch open-end wrench. Screw driver. 

% 6"iiich open-end wrench. Long nose pliers. 

Spring type bearing pull- Hammer, 

ers. Brass drift. 

(1) Remove jacket tube. %-inch socket wrench. 

i/^-inch open-end wi-ench. 

Loosen upper cover cap screw BCBXIBG and nut BBBXIB and 
pull out jacket tube RG-r789-38%. 

(2) Remove bearing unit from Spring type bearing pullers. 

tube. 

Take out spring RG-401105 and spring seat RG-028104 and pull out 
bearing unit RG-065996 (fig. 114) . 

(3) Remove housing upper %e-inch open-end wrench, 
cover. 

Remove 4%-inch cap screws BCBXlCC and lock washers BECXlK 
from housing upper cover and take off cover RG-266000 and adjust- 
ing shims RG-033042, RG-033036 and RG-033037. 



242 



TM 9-1709 

CHASSIS AKD BODY FOR SOOUT CiARS M3A1 49 

(4) Remove housing side cover. i/2"ii^ch socket wrench. 

Take out 6'%6-i»ch cap screws BCAXlBD and lock washers 
BECXIH and remove side cover RG-T265001 and gasket RG-T269000. 

(5) Remove steering arm as- %e-inch socket wrench, 
sembly and lever shaft. Light file. 

Small puller. 

Take off lever shaft nut BBDX2E and lock washer BECX2T. 
Dress end of lever shaft splines with a file to remove any burs and 




RA PD 6373 

Figure 114. — Steering gear jacket tube bearing removal. 

pull off steering arm assembly RG-502485. Remove lever shaft 
assembly RG-7736-6-1/2 from opposite side of gear case. 

(6) Remove cam and wheel None, 
tube assembly. 

After lever shaft has been removed, the wheel tube assembly 
RG-7755-47-13/16 can be withdrawn from housing. 

(7) Disassemble bearings. Screw driver. 

Long nose pliers. 

Remove bearing retaining rings RE-400005, bearing cups RG-40021 
and 28 balls CCAXlE. 

(8) Remove housing bushings. Hammer. 

Brass drift. 

243 



TM: 9-1709 

49-50 ordnance maintenance 

Drive out inner bushing EG-068002 and outer bushing RG-068003 
and oil seal EG-032077 from housing. 

i. Drag link (fig. 115). 

Remove working parts of link. Drag link adjuster or wide 

screw driver. 

Turn out adjusting plugs SU-80P06 and shake out two bearings 
SU-12R2, and one seat SU-80P03, spacers SU-80P11, spring 
SU-80P10 from each end. 

50. Maintenance and adjustments. — a. Steering gear mainte- 
nance. — (1) After disassembly, clean all parts thoroughly of grease, 
oil, aiid dirt. 

(2) Check horn button and jacket tube springs for softness or 
breaks and replace if necessary. 

(3) Check bearing races and balls and steering arm ball for wear, 
chipping, and scoring. Repair or replace if necessary. 

(4) Re]3lace housing bushings if excessive wear or scoring is vis- 
ible and install a new oil seal if the old one is damaged. 

(5) Inspect cam closely for wear or chipping and replace if neces- 
sary. 

(6) Check lever shaft studs for misalinement, bending, and wear, 
and if necessary, replace with new shaft assembly. 

h. Drag link mmntenance. — (1) After disassembly, clean all parts 
thoroughly in solvent, dry-cleaning. 

(2) Check ball seats for wear and scoring and replace with new 
parts if necessary. 

(3) If springs have become soft or broken, replace with new ones, 
c. Steering gear adjustments. — After the steering gear has been 

reassembled, the adjustments given below can be made with the steer- 
ing gear either installed in the vehicle or dismounted. With the 
steering gear installed it is necessary first to disconnect the drag link 
from the steering gear arm, and loosen the instrument panel bracket 
liolding the steering gear jacket tube. Follow the specific instruc- 
tions indicated in exactly the order given. 

(1) Ca'tn end-flay (fig. 116). — Ejid-play shows np as play in the 
steering wheel tube and cam ball bearings. 

(a) Loosen housing side cover screw and lock nut to free the studs 
in the cam groove. 

(h) Remove the four upper cover screws, and raise cover about i^ 
inch to permit removal of adjusting shims. A combination of 0.002-, 
0.003-, 0.010- and 0.030-inch shims are used between paper gaskets. 



244 



TM 9-1709 

CHASSIS A3siT) BODY FOK SCOUT OARS M3A1 50 




245 



TM 9-1709 
50 



■OEONANiCE MAINTENANCE 



(c) Clip and remove one 0.003-inch shim, or more, as required. 
Replace cover and tighten screws. 

{d) Adjust side cover adjusting screw to a barelj' perceptible drag 
so that the steering wheel can be turned freely. 

(e) Check adjustments and, if necessary, repeat operations to re- 
move or replace more shims. 

(2) Lever shaft evd-play (fig. 117) . — Backlash of the tapered studs 
in the cam groove shows up as end-play of the lever shaft and as back- 
lash at the steering wheel and the steering arm ball. Adjustment 
is made within the high range through the midposition of the stud 



f SCREW -BCBX ICC 
-iWA^M^P.. LOCK - BECXIK , 



SH!M (,002» -.■■An52j511 
• ■ 5.003) --A 173262 K 
i.OlO! -AI86512I 




RA PD 7433 



FIGURE 116. — Steering gear cam eiiil-play adjustmeul. 



travel. The cam groove is purposely cut shallower, therefore nar- 
rower, in the midposition range to provide close adjustment where 
the straight ahead driving action takes place. It also makes this 
close adjustment possible after normal wear occurs without causing 
binding elsewhere. Therefore, adjust through this midposition. Do 
not adjust in positions off midposition as backlash at these points is 
normal and not objectionable. 



246 



TM 9-1709 

CHASSirS AND BODY FOE SCOUT ClARS M3A1 50 

{■a) Tighten the side cover adjusting screw until a very slight drag 
is felt through the midposition high range when turning the steering 
wheel slowly from one extreme to the other. 

Caution: The gear must not bind at any place ; only a very slight 
drag should be felt. A closer adjustment will not correct any steering 
condition, but will damage and wear the steering gear parts and 
impair operation. 

(i) Wlien proper adjustment has been made, tighten the lock nut 
and give the steering gear the final test. 

(c) Make sure that the steering ball arm is tight on the splined 
shaft and that the lock washer and nut are also tight. 

(3) Precautions. — :The foregoing cam and lever shaft end-play 



SCREW -AJ 752541 
NUT -Ai 75255 (' 



Figure 117. — Steering gear lever shaft end-play adjustment. 

adjustments are usually all that are required unless there are worn 
parts that need replacing; in that case disassemble and inspect steer- 
ing gear. Always adjust cam end-play first. Do not attempt to cure 
wander, shimmy, or road shock by tightening the steering gear to 
dampen out these difficulties. Adjust the steering gear only to remove 
play in it. 



247 



TM 9-1709 

50 



O'R'DKANCE MAINTENANCE 



(4) Goluvm alinement. — (a) Tighten the U-bolt at the instrument 
panel steering column support. 

{b) Turn the steering wheel to see if stiffness or binding exists. 
If so, the gear has been adjusted too tight or the steering column is 
out of alinement. The steering column must not be sprung in any 
direction. 




FiGUKH lis. — Steering arag link adjustment. 



(c) Check the steering gear frame bracket for tightness to the 
frame. It should hold the gear assembly rigidly and should not 
spring when the wheel is turned after the drag link is connected and 
the wheels are on the ground. 

d. Drag livk adjustments. — The only adjustment possible on the 
drag link is the adjustment of the end plugs. This is made after 
the link has been installed on the ear (fig. 118). Using a drag 

248 



TM 9-1709 

CHASSIS AND BODY FOR SCOUT CARS M3A1 50-51 

link adjuster, tighten the plugs just enough to prevent excessive 
looseness of the steering arm ball in the ball seats but not enough to 
cause binding. Back off enough to enable cotter pins to be inserted 
in the drag link tube and end plugs to secure the plugs in position. 
e. Service data. 

Steering gear : 

Steering post bearings No perceptible end play. 

Lever sliaft thrust adjust- Sci-ew. 

ment 

Lever shaft end play 0.002 to 0.003 in. 

Clearance between lever shaft and bushings : 

Outer 0.0005 in. 

Inner 0.0025 in. 

51. Reassembly of components. — a. Steering gear. — Before as- 
sembly, lubricate all parts thoroughly with wheel bearing grease. 
Tools: 

Hammer. i/2-inch socket wrench. 

Bushing driving tool. %g-inch open-end wrench. 

Screw driver. %-inch open-end wrench. 

Soft metal hammer. Tube of smaller diameter than 
l^e'i^^ch socket wrench. jacket tube. 

(1) Keplace busliings and oil Hammer. 

seal. Bushing driving tool. 

Drive bushings into housing and then replace oil seal. 

(2) Replace bearings. Screw driver. 

Set balls on inner race, replace outer race (cup) and lock in place 
with retaining ring. 

(3) Install cam and tube as- None, 
sembly. 

Set cam into gear housing, 

(4) Replace lever shaft and l%e-inch socket wrench, 
steering arm assemblies. Soft metal hammer. 

Insert lever shaft into housing until studs mesh with cam. Force 
steering arm on lever shaft splines and if necessary tap with hammer. 
Replace lock washer and nut and tighten assembly. 

(5) Repliice housing side cover. i/2-iiich socket wrench. 

Place a new gasket between cover and housing and tighten down 
cover with cap screws and lock washers. 



249 



TM 9-1709 

51-52 OEDNANCE MAINTEKANCE 

(6) Eeplace housing upper. %6-inch open-end wrench. 

Set adjusting shims and cover on housing and replace bolts and 
lock washers. 

(7) Eeplace bearing unit in Tube of smaller diameter than 
jacket tube. jacket tube. 

Push bearing and seat into place and then replace spring. 

(8) Eeplace jacket tube. i^'i^ch socket wrench. 

i/^-inch open-end wrench. 

Seat tube in housing upper cover and tighten cover clamp bolt 
and nut. 

(9) Adjust steering gear. 
See paragraph 50c. 

h. Drag link. 

(1) Eeplace components in axle Drag link adjuster or wide 
end of link. screw driver. 

In the order named, set bumper seat, spacer, spring, and bearing 
seats into axle attaching end of link and turn up end plug enough 
to hold pax-ts in place. 

(2) Eeplace components in Same as above, 
steering gear end of link. 

Set bearing seats, spring, spacer, and bumper seat in order into 
steering geai' end of link and re])lace end plug. 
52. Installation of assembly. — a. Steering gear. — Tools : 

%-inch socket wrench. %-inch open-end wrench. 

%6"i'it:h socket wrench. Screw driver. 

li/4-inch socket wrench. Spring pullback pliers. 

(1) Attach assembly to car. 'j/g-inch socket wrench. 

%-inch open-end wrench. 

Hold steering gear assembly in its running position and bolt hous- 
ing to frame bracket with bolt, lock washer, and nut. Eeplace 
frame bracket cap and tighten it with lock washers and cap stud 
nuts. 

(2) Eeplace jacket supporting %6-inch socket wrench. 
U-bolt. 

Line up steering column at instrument panel support bracket and 
replace U-bolt lock washers and nuts. Tighten nuts. 



250 



TM 9-1709 

CHASSIS AN'D BODY FOB SCOUT CARS M3A1 52 

(3) Eeplace steering wheel. 114-iiich socket wrench. 

Force steering wlieel onto steering tube and fasten in place with 
wheel nut. 

(4) Replace ba.se plate and Screw driver, 
horn button asseniblj'. 

Set ba.se plate into wheels opening and tighten down with three 




RA PD 7487 



A. Plug SU-SOl'iii). C. Drag link as.seinbly SU-SOPIO:!. 

h. Arm, w/l)iill, assembly I{(;-."'>0:i48."i. 

FiGUiiM 119. — steering drag link reiilacement. 

screws. Place washer, spring, cup, and horn button in place in the 
order given and lock assembly by pushing down on button and rotat- 
ing it one-sixth turn. 

(5) Connect horn button to Spring pullback pliers, 
electrical system. 

251 



TM 9-1709 
52-53 



OKDNANCE MAINTENAN.CE 



Eeconnect horn button cable terminal at bottom of steering gear 
housing and at the same time attach brake and clutch pullback 
springs to housing. 



h. Drag linh. — Tools : 

Drag link adjuster or wide 

screw driver. 
Screw driver. 
(1) Replace link. 



%-inch open-end wrench. 
%6"iiich open-end wrench. 
% 6-inch socket wrench. 
Drag link adjuster or wide 
screw driver. 

Set steering gear in midposition for straight ahead driving. Place 
wheels in straight ahead driving position and slip drag link into 
steering gear and axle steering arm balls (fig. 119). Tujn up end 
plugs. 

(2) Adjust drag link. 
See paragraph ^Qd. 

(3) Adjust steering gear. Screw driver. 

%-inch open-end wrench. 
%6-iiich open-end wrench. 



% 



-inch socket wrench. 



Check steering gear and if necessary, adjust assembly by following 
steps outlined in paragraph 50(7(1) to (4), inclusive. 

Seotiok XIII 

CONSOLIDATED SERVICE DATA (FITS AND 

CLEARANCES) 

Paragraph 

Master cylinder 53 

Wheel brakes 54 

Drive shaft bralie - 55 

Radiator 56 

57 

- 58 

59 



Front springs 
Rear springs. 
Steering gear. 

53 



Master cylinder. 

Cylinder diameter 1% in. 

Piston clearance 0.001 to 0.004 in. 

Piston return spring, pressure 

at 227/54 inches 12 lb. 



252 



TM 9-1709 

CHASSIS AJSro BODY FO-R SCOUT CARS M3A1 54-58 

54. Wheel brakes. 
Wheel cylinders : 

Piston clearance : 

.Front 0.001 to 0.005 in. 

Eear 0.001 to 0.005 in. 

Front and rear shoe adjust- 
ment : 

Cam (top of shoe) 0.010 in. 

Eccentric (bottom of shoe) _ 0.005 in. 
Brake return springs : 
Front cylinder piston : 

Free length 2% in. 

Pressure at 1% inches. 1 to 1% lb. 
Rear cylinder piston : 

Free length 3l^ in. 

Pressure at 2 inches 1^/2 to 2 lb. 

Shoe return springs : 

Free length 7%6 in- 

Pull at 814 inches 75 to 85 lb. 

Brake drum: 

Eegrinding limits 0.030 in. 

55. Drive shaft brake. 
Brake adjustment : 

Clearance, linings to disk _ %2 in. 
Brake release spring: 

Free length.^ 4% in. 

Pressure at 4% e inches 60 lb. 

56. Radiator. 

Stay rod studs (each side of 
radiator) : 

- Size 1/2-20 SAE threads (1 in. 

X 11^ in.) 
Bottom mounting studs: 

Size . 1/2-20 SAE threads (1 in. 

X 2% in.) 

57. Front springs. 

Spring bushings (bronze) 0.003 in. 

Inside diameter 1 in.-0.005 in. 

58. Rear springs. 

Spring bushings (bronze) 0.003 in. 

Inside diameter ly^g in.-0.005 in. 



253 



TM 9-1709 

59-60 OBDNAKCE jMAIlNrTENANCE 

59. Steering gear. 

Steering post bearings Xo perceptible end play. 

Lever shaft thrust adjustment- Screw. 

Lever shaft end play 0.002 in.-0.003 in. 

Clearance between lever shaft 
and bushings: 

Outer 0.0005 in. 

Inner 0.0025 in. 

Section XIV 

CARE OF UNITS IN EXTEEME TEMPERATURES OE 
UNDER UNUSUAL CONDITIONS 

Paragraph 

In extreme temiiera lures 60 

After fording streams or in flood conditions 61 

In muddy or sandy terrain 62 

60. In extreme temperatures. — Temperatures ranging between 
— 10° F. and —30° F. ai-e designated as low, and temperatures be- 
low — 30° F. as extreme. OFSB 6-11 covers lubrication for tem- 
peratures below —10° F, 

a. Brake system. — After driving in sleet or deep snow, in tem- 
peratures below freezing, test brakes before making another trip. 
After a long stop, make certain that the linings are not frozen to 
the drums. If possible, leave vehicle in a warm garage luitil the 
ice has melted. If this is not possible, pour boiling water over the 
frozen drum, immediately before operation, and drive vehicle with 
brakes lightly applied until they dry out, taking care to prevent 
burning the brake linings. 

h. Cooling system. — (1) Fill the cooling system Avith an antifreeze 
solution, employing either approved alcohol, or ethylene glycol. Alco- 
hol may be used as antifreeze but it has the disadvantage of evaporat- 
ing out of solution. Thoroughly clean and tighten the system before 
adding any antifreeze (see TM 9-705). The following table gives 
the amount of antifreeze necessary for various temperature con- 
ditions; however, an antifreeze solution hydrometer should be used 
as a check. 



254 



TM 9-1709 

CHASSIS AKD BODY FOR SCOUT CARS M3A1 80-61 
ANTIFREEZE CHARTS 



Temperature 


Denatured 
alcohol 


Ethylene glycol 
(Prestone) 


Temperature 


Denatured 
alcohol 


Ethylene glycol 
(Prestone) 


+ 20° F. 
+ 10° F. 

0° F. 


(Quarts) 

3M 
7 


(Quarts) 

3 

i'A 
6 


- 10° F. 
-20° F. 
-30° F. 


(Quarts) 

8 

9 

10 


(Quarts) 
7 
8 
8/2 



(2) To prevent excessive cooling of the engine and poor combus- 
tion, the radiator shutters should be partly closed or the radiatoi' 
core partly covered with a tarpaulin or other suitable material. 

c. Battery. — (1) The freezing point of battery electrolyte depends 
upon its specific gravity. There is little danger of freezing except 
with a discharged battei'y. In order to avoid freezing of the electro- 
lyte, always keep the battery in a fully charged condition. The fol- 
lowing table shows the freezing points of electrolyte : 

FREEZING POINTS OF ELECTROLYTE 



Specific gravity 


Freezing tem- 
perature 


Specific gravity 


Freezing tem- 
perature 


1.120- . 


+ 14° F. 

+ 6° F. 

-17° F. 


1.225 


-35° F. 


1.150 


1.250 


— 62° F. 


1.200 


1.275. 


— 85° F. 









(2) When it is necessary to add water to the battery in freezing 
weather always do it just before running the engine. If the tempera- 
ture is extremely low, start the engine so that the battery is charging 
before water is added. The reason for this is that water, being lightei' 
than electrolyte, will remain on the surface and freeze unless it is 
thoroughly mixed with the electrolyte. 

d. Fuel system. — (1) In extreme temperatures, insulating the fuel 
lines with asbestos tape or other asbestos compound will help prevent 
ice from forming inside the lines. 

(2) Small quantities of denatured alcohol, about 1/2 pint to a tank 
of fuel, will reduce difficulties from water in gasoline. 

(3) Any arrangement for directing the heat from the exhaust 
manifold back over the fuel lines and tanks is beneficial. 

61. After fording- streams or in flood conditions.— After ford- 
ing shallow streams it is not usually necessary to take any preventive 



25.5 



TM 9-1709 

61-62 ORDNANCE MAINTENANCE 

maintenance steps. However, if the units have been submerged for 
several hours or more due to fording deep streams or being in a 
flooded area, it is necessary to remove all foreign matter which may 
have accumulated. This is done by thoroughly dismantling units sub- 
merged, washing each part in solvent, dry-cleaning and then spread- 
ing a thin film of oil, engine, over the parts. In instances when 
emergency requirements make an immediate, complete, cleansing im- 
possible, some damage may be prevented and the vehicle kept in serv- 
ice by the following procedure: 

a. General. — Lubricate the steering gear and all pedals, shafts, and 
linkages beneath the hood and on the chassis. 

h. Brake system. — (1) Remove the brake drums and wipe the lin- 
ings and anchor pins clean. Lubricate the pins. 

(2) Drain the brake lines, flush the system with alcohol, and refill 
with new bi'ake fluid. 

c. Cooling system. — \i. any grit or dirty water has seeped into the 
cooling system, drain out the liquid. Then flush the system thoroughly 
and refill with clean liquid. Clean the outside of the radiator case. 

d. Electric lighting system,; battery and accessories. — ^Wipe all 
wires and contact points clean and dry. Clean the battery terminals 
and check the battery for signs of discharging due to short-circuiting 
by the water or other foreign mattei-. Recharge battery, if necessary. 

e. Fuel system,. — If any part of the fuel system has been submerged, 
drain and flush the system thoroughly and refill with gasoline, using 
1/2 pint of alcohol to each tank full of fuel to counteract the efl^ect of 
the water. If any grit has found its way into the carburetor, it may 
be necessary to remove it and clean the jets and needle valve. 

Note. — At tlie fli'st opiJortiine time, completel.v disassemlile ench unit and clean 
thoroughly. 

62. In muddy or sandy terrain. — No data on care of units after 
traversing deep muddy terrain or care in sandy terrain and deserts 
is available at this time. This information will be furnished by field 
service maintenance division. 



2r)6 



TM 9-1709 



Appendix 
LIST OF REFERENCES 

1 . Standard Nomenclature Lists. 

a. Cleaning, preserving, and lubricating ma- 
terials SNL K-1. 

h. Scout cars M3A1 SNL G-67. 

Current Standard Nomenclature Lists are as 
tabulated here. An up-to-date list of 
SNL's is maintained as the Ordnance 
Publications for Supply Index OPSI. 

2. Explanatory publications. 
a. Automotive materiel. 

Automotive brakes : TM 10-565. 

Cold weather operation of automotive equip- 
ment - OFSB 6-G-3. 

Fuels and carburetion TM 10-550. 

Maintenance and care of pneumatic tires TM 31-200. 

Military motor transportation TM 10-505. 

Military motor vehicles AR 850-15. 

Motor transport FM 25-10. 

Motor transport circular 1-10 QMC. 

Motor transport technical service bulletins QMC. 

Scout cars M3 ; M3A1 ; and 4.2 mortar motor 
carriage M2 TM 9-705. 

Scout cars M3A1; power plant (Buda 
6DT317 Diesel) TM 9-1708. 

Scout cars M3A1; power plant (Hercules 
DJXD Diesel) TM 9-1707. 

Scout cars M3A1; power plant (Hercules 
JXD gasoline) TM 9-1706. 

Army Motors monthly (QMC motor trans- 
port school) QMC. 

The internal combustion engine TM 10-570. 

The motor vehicle- TM 10-510. 



4TTL'29° 42- —17 



257 



TM 9-1709 

h. Cleaning, preserving, and lubricating ma- 
terials TM 9-850. 

c. Automotive electricity TM 10-580. 

d. Lubrication. 

Automotive lubrication TM 10-540. 

Car, scout, M3A1 OFSB 6-11. 

Car, scout TM 9-705. 

e. Maintenance and repair. 

Automotive power transmission units TM 10-585. 

Echelon system of maintenance TM 10-525. 

Hand, measuring, and power tools TM 10-590. 

Inspection TM 10-545. 

Maintenance and I'epair TM 10-520. 

Sheet metal work, body, fender, and radiator 

repairs TM 10-450. 

/. Miscellaneous. 

Fire pi'evention, safety precautions, acci- 
dents TM 10-360. 

List of training publications FM 21-6. 

Loading of mechanized and motorized ariuy 
equipment on open top railroad equip- 
ment Association of American Railroads. 

g. Storage of motor vehicle equipment AE 850-18. 



I A. n ofi2 11 (a-3i-42).i 

258 



TM 9-1709 



INDEX 

Paragraph Page 

Accelerator 6 7 

Air cleaner 6, 38 6, 193 

Ammunition racks 6 4 

Assembly : 

Installation 52 250 

Removal . 48 237 

Axles. {See Front axle and Rear axle.) 

Batterj' 6,23-29 5,127 

Body: 

Disassembly . 7 9 

Inspection 

Maintenance. - . 

Brake : 

Description 

Fluid 

Lines 

Linkage .____ _ 6,12 

Systems___ 10-lJ 

Bumpers .__ . _ 

Carburetor 

Care of units under unusual conditions. . 

Caster and chamber 

Choke 

Clutch . 

Consolidated service data _ 

Cooling system . 

Curtains . . 

Cylinder, master _„ 



6 


4 


7 


9 


10 


33 


6 


7 


6 


5 


6, 12 


5,36 


10-18 


33 


6, 33 


3, 182 


6,38 


6, 193 


60-62 


254 


6 


4 


6 


7 


6 


8 


53-59 


252 


19-22 


113 


6 


4 


13 


44 



Data, consolidated service . . 53-59 252 

Disassembly: 

Drag link 

Steering gear 

Distributor . 

Doors .. 

Drag link 

Drive shaft brake 6, 18, 55 

Electric lighting system 23-29 127 

Engine: 

Compartments 6 7 

Lubrication ^ 6 6 

Mechanism. _ _ 6 9 

259 



49 


244 


49 


242 


6 


6 


6 


4 


•52 


232 


55 


8, 96, 253 



TM 9-1709 

INDEX 

Fan: Paragraph Page 

Assembly 22 127 

Inspection 6 6 

Fenders: 

Inspection 6 4 

Sheet metal 8 23 

Fire extinguisher 6 7 

Frame __ 6,30-33 171 

Front — 

Axle 6 5 

Roller 6 4 

Springs 43, 57 210,253 

Fuel- 
Filter 6 6 

Leaks 6 7 

Lines 6,37 6,189 

Pump 6,38 6,193 

System 34-38 182 

Gages . 6 7 

Cxaskets 6 7 

Gearbox 6 8 

Glass 6 4 

Gvm rail pads 6 7 

Headlamps 27 162 

Headlight guards 6 4 

Heater 25 138 

Hood 6 4 

Horn 6,26 7,141 

Inspection (see also names of parts) : 

Form used 5 3 

Practical application 6 3 

Technical, description 4 3 

Instrument and gages _ 39-42 193 

Instrument panel _ 8 24 

Lights 6 4 

Louver control lever 6 7 

Lubrication, engine _ 6 6 

Maintenance: 

Drag link 50 244 

Steering gear 50 244 

Maintenance, service 2, 3 2 

Marker lamps 28 160 

Master cylinder . 13,53 44,252 

Meters ._ 6 7 

Muffler 6 6 

Nomenclature lists App. 257 

260 



TM 9-1709 

INDEX 

Oil — PnniKiaph Pukp, 

Filter 6 (i 

Lealvs _ 6 7 

Paint .._ 6 4 

Panellights_ 6 4 

Pedals , _ _^_ 6 7 

Pintle.. . 6,31 4,176 

Propeller shafts . 6 5 

Publications, explanatory App. 257 

Radiator 6, 21, 56 4, 6, 117, 

253 
Rear — 

Axle. 6 6 

Springs___ 44,58 216,253 

Reassembly of components: 

Drag link . . 51 250 

Steering gear . .. 51 249 

References, list . App. . 257 

Roller ... 32 176 

Running boards 6 4 

Seats 6 7 

Service maintenance .. 2, 3 2 

Sheet metal . 8 23 

Shielding ._ 6 6 

Shock absorbers . 6,45 5,220 

Shroud _ 6 6 

Speedometer .. 6,42 8,204 

Springs: 

Front__ . 43,57 210,253 

Inspection .. . _ ._ . 6 "5 

Rear .. _ 44,58 216,253 

Steering : 

Gear .- _ .6,46-52,59 5,232,254 

Mechanism . . 6 8 

Switches ,. 6 7 

Tachometer cables — ._ . 6 8 

Tailpipe .- . .. 6 6 

Taillamp 29 161 

Temperatures, extreme . . ... — 60-62 254 

Tires — - - -. . 6 4 

Toolboxes.- 8 25 

Top ... - ... 6 4 

Top bows 6 7 

Tow hooks. 6,31 3,176 

Tow-in . 6 4 

Transfer case - 6 ^5 

Transmission 6 5 

261 



TM 9-1709 

INDEX 

Trouble shooting: Paragraph Page 

Brakes . U 33 

Cooling system 20 114 

Drag link 47 236 

Fuel system . 35 184 

Steering gear. 47 236 

Vacuum booster 0, 14 5, 53 

Ventilator controls 6 7 

Voltage regulator 6 8 

Water — 

Leaks 6 8 

Pump 6,22 6,127 

Wheels : 

Brakes 17,54 77,253 

Inspection 6 5 

Windshield wipers 6, 9 7, 25 

Wiring . 6 8 



By obdek or thi: Seceetaky of War : 

G. C. MARSHALL, 

Chief of Staff. 

OFFICIAL, : 

J. A. ULIO, 

Major General^ 

The Adjutant General. 
DISTK1BUT10^' : 

E 9 (2) ; IBn 9 (1) ; IC 9 (3) (or 91 medium or heavy main- 
tenance companies). 
(For explanation of symbols see FM 21-6.) 



o 



262